The Color Lexicon of American English: Delwin T. Lindsey Angela M. Brown
The Color Lexicon of American English: Delwin T. Lindsey Angela M. Brown
org/content/14/2/17 1
         This article describes color naming by 51 American English–                languages. The third issue concerns the evolution of a
         speaking informants. A free-naming task produced 122                       language’s color lexicon as color categories change. The
         monolexemic color terms, with which informants named                       present study seeks to address some of these issues by
         the 330 Munsell samples from the World Color Survey.                       analyzing the color-naming behavior of a group of native
         Cluster analysis consolidated those terms into a glossary of               English-speaking informants drawn from the relatively
         20 named color categories: the 11 Basic Color Term (BCT)                   culturally homogeneous population of Ohio State Uni-
         categories of Berlin and Kay (1969, p. 2) plus nine nonbasic
                                                                                    versity faculty, staff, and students.
         chromatic categories. The glossed data revealed two color-
         naming motifs: the green–blue motif of the World Color
         Survey and a novel green–teal–blue motif, which featured
         peach, teal, lavender, and maroon as high-consensus terms.                 Berlin and Kay
         Women used more terms than men, and more women
         expressed the novel motif. Under a constrained-naming                         The context for this work is the classic theoretical
         protocol, informants supplied BCTs for the color samples                   analysis of cross-cultural differences in color categories
         previously given nonbasic terms. Most of the glossed                       by Berlin and Kay (1969). On the basis of their study of
         nonbasic terms from the free-naming task named low-                        98 world languages, these authors advanced two
         consensus colors located at the BCT boundaries revealed by                 conjectures about the differences they observed. Their
         the constrained-naming task. This study provides evidence                  first conjecture was that there is a limited set of basic
         for continuing evolution of the color lexicon of American                  color terms (BCTs) in most languages, which are distinct
         English, and provides insight into the processes governing                 from other color terms that an individual might use to
         this evolution.                                                            name colors. According to this first conjecture, the
                                                                                    colors in the lexicon of each language are a subset drawn
                                                                                    from a universal set of 11 color categories, which are
          Introduction                                                              closely related to the BCTs of English and other
                                                                                    languages spoken in technologically advanced societies.
                                                                                    Berlin and Kay’s second conjecture was that color
            Humans can discriminate on the order of 106 different
         colors, many more colors than any individual can name                      lexicons evolve from simple to complex, along highly
         reliably. These colors fall into a much smaller number of                  constrained paths, starting from two BCTs correspond-
         categories that speakers in a language community can                       ing to warm-or-light and dark-or-cool categories in the
         name and can use among themselves to communicate                           simplest lexicons and ending with the 11 BCTs of
         about color. People around the world differ greatly in the                 languages like English.
         number of these named color categories. However, despite
         more than 150 years of research, several unresolved issues
         persist regarding cross-cultural differences in color                      The first conjecture: The basic color terms and
         lexicon. One of these issues concerns how best to                          their universality
         characterize the relative importance of terms in a
         language’s color lexicon. Another is how to compare and                       Berlin and Kay proposed that most world languages
         contrast color lexicons across the world’s 7,000 living                    include a set of BCTs in their lexicons. According to
         Citation: Lindsey, D. T., & Brown, A. M. (2014). The color lexicon of American English. Journal of Vision, 14(2):17, 1–25, http://
         www.journalofvision.org/content/14/2/17, doi:10.1167/14.2.17.
         doi: 10 .116 7 /1 4. 2. 1 7                 Received August 12, 2013; published February 25, 2014           ISSN 1534-7362 Ó 2014 ARVO
         their definition, the BCTs are monolexemic (single,            Boynton and Olson to Japanese color terms, the results
         noncompound words that lack modifying prefixes or              were generally similar. Particularly, Uchikawa and
         suffixes) and are used principally in reference to the         Boynton also found that similar terms—hada (skin),
         colors of things, without constraint as to what thing is      meaning tan, and mizu (water), meaning light blue—
         being described. Moreover, BCTs are present in the            may be making their way into the Japanese basic color
         idiolects of all informants speaking a given language,        lexicon. Similarly, several investigators have discussed
         are used in a consistent way across all informants, and       terms for light blue, which might be a 12th BCT in
         can be used to partition color space exhaustively. By         several other languages (Al-Rasheed, Al-Sharif, Thabit,
         these and other criteria, Berlin and Kay proposed 11          Al-Mohimeed, & Davies, 2011; Borg, 2007; Friedl,
         English BCTs: black, white, red, yellow, green, blue,         1979; Ozgen & Davies, 1998; Thierry, Athanasopoulos,
         brown, orange, pink, purple, and gray. In contrast to         Wiggett, Dering, & Kuipers, 2009; Winawer et al.,
         the BCTs, most languages, including English, have             2007).
         additional color terms that fail to meet one or more of          The issue of consensus, which was central to the
         these criteria: Either not everybody uses them (e.g.,         definition of the BCTs, has turned out to be unex-
         chartreuse in English), they are not monolexemic (e.g.,       pectedly complex. Boynton and Olson (1987) discov-
         light blue in English) or they are restricted as to what      ered clear individual differences among their observers,
         they can name (e.g., blond in English).                       and Uchikawa and Boynton (1987) found that there
            BCTs name basic color categories. While the terms          were no 100% consensus colors among the 430 OSA
         themselves are specific to a language (the same samples        samples corresponding to the Japanese colors akai
         might be called red in English, rouge in French, akai in      (red), kuroi (black), kiroi (yellow), and aoi (blue).
         Japanese, and so forth), Berlin and Kay’s first                Similarly, Sturges and Whitfield (1995) reported no
         conjecture was that the color categories these terms          100% consensus samples for yellow, pink, orange, and
         refer to are universal across languages. While not every      white. Furthermore, the issue of consensus is compli-
         language has every color category named within its            cated by the existence of synonyms for many colors:
         lexicon, Berlin and Kay proposed that ‘‘a total               Different words might be used by different informants
         universal inventory of exactly eleven basic color             speaking the same language to name the same or highly
         categories exists from which the eleven or fewer basic        similar color categories (violet and purple might be
         color terms of any language are always drawn’’ (1969,         synonyms in English, hairoi and guree (gray) might be
         p. 2).                                                        synonyms in Japanese).
            In the years since Berlin and Kay’s work, an                  Moreover, Lindsey and Brown (2006, 2009) have
         enormous amount of research has been done to                  shown that, strictly speaking, high consensus may be
         determine whether their first conjecture is correct. Some      the exception rather than the rule among the color
         investigators have addressed the issue of whether the         lexicons in world languages. They examined the World
         inventory of terms listed, and only those color terms,        Color Survey (WCS) data set (Kay, Berlin, Maffi,
         fulfill Berlin and Kay’s definition of BCTs in every            Merrifield, & Cook, 2010), a large database of color
         known language. This literature as a whole suggests           naming by 2,616 informants, each speaking one of 110
         that at least some BCTs exist in every language that has      unwritten languages and living a traditional lifestyle far
         been examined, but that there might be more than 11 of        from daily influences of modern technology. Each WCS
         them in some cases. Boynton and Olson (1987, 1990;            informant was tested with a standard set of 330
         for a review, see Boynton, 1997, pp. 144–145) used            Munsell color samples of varying hue, value, and
         performance-based measures of color naming to                 chroma (shown in Figure 1a), one at a time, in a fixed
         evaluate the special status of Berlin and Kay’s English       pseudorandom order, and provided a color name for
         BCTs. When Boynton and Olson’s American English–              each. Lindsey and Brown (2006) used cluster analysis to
         speaking subjects were allowed to use any monolexemic         extract a glossary of universal terms used by WCS
         terms to name colors in the Optical Society of America        informants. A second cluster analysis (Lindsey &
         (OSA) Uniform Color Space, they used BCTs with                Brown, 2009) on the glossed color-naming systems of
         significantly greater speed, consensus, and consistency        WCS informants revealed that the color vocabularies of
         than nonbasic terms, much as Berlin and Kay                   WCS informants clustered into four distinct vocabulary
         predicted. Boynton and Olson also noted that a 12th           types (‘‘motifs’’), where each motif had its own
         term—peach—might, over time, assume BCT status in             characteristic set of color terms. Crucially, multiple
         terms of naming speed, consensus, and consistency.            motifs occurred side by side within most WCS
         Sturges and Whitfield (1995) found similar results using       languages. This meant, for example, that some speakers
         Munsell color samples and British English–speaking            of a language might use only color terms glossed as
         subjects, except that they suggest that the 12th term         black, white, and red, while others might use five color
         might be cream (Sturges & Whitfield, 1997). When               terms, and still others might use 10 color terms. The
         Uchikawa and Boynton (1987) applied the methods of            lack of consensus revealed by Lindsey and Brown’s
         Figure 1. (a) Color chart approximating the samples used in this study, arranged in the order of their Munsell hues (horizontal
         direction of the chart) and values (vertical direction). (b) Sample holders, shown on Color-aid N4.5 background.
         2009 analysis was not merely quibbling about where the              to languages that have fewer color terms by ‘‘succes-
         boundaries are located in the stimulus set. Rather, it              sive differentiation of previously existing color cate-
         indicates a profound failure of consensus among the                 gories’’ into smaller, more accurately named
         speakers of most WCS languages.                                     subcategories (Kay & McDaniel, 1978, p. 640). This
            The work of Lindsey and Brown (2009) revealed a                  process follows a series of stages, in a fairly
         new kind of universality in addition to the one                     constrained evolutionary trajectory. According to the
         proposed by Berlin and Kay (1969). Whereas the WCS                  second conjecture, this continues until the lexicon
         languages differed from one another in how many                     reaches a stage equivalent to the 11 BCTs of English
         individuals used each of the four motifs, the motifs                and other languages spoken in industrialized societies.
         themselves occurred worldwide, even though the                      Thus, Berlin and Kay’s second conjecture is that color
         informants who used each of the motifs spoke                        lexicons evolve, that they follow a prescribed trajec-
         languages with no known historical linguistic ties. This            tory, and that color terms are added by ‘‘partition’’ of
         suggested that analysis of color naming must be                     existing named color categories.
         conducted at the level of each informant’s idiolect,                   In a sense, the strict ordering proposed by Berlin and
         rather than at the level of the language shared among a             Kay resembles a theory of biological development, in
         community of informants. Furthermore, the results                   which maturation of the organism occurs in stages
         revealed the usefulness of cluster analysis as an                   following a single prescribed trajectory, with minor
         objective means of comparing color naming across                    differences from individual to individual. More recent
         languages, thus avoiding many of the pitfalls associated            work by Kay et al. (2010) has relaxed and generalized
         with glossing color terms by traditional lexicographic              the evolutionary hypothesis considerably, to allow for
         techniques.                                                         some languages that do not fit neatly into one of Berlin
                                                                             and Kay’s original stages and to suggest a much less
                                                                             constrained, more diverse range of evolutionary path-
         The second conjecture: The evolution of BCTs                        ways. The more diverse range of trajectories proposed
                                                                             by Kay et al., 2010 resembles ontological evolution
            Berlin and Kay’s second conjecture was that                      more closely, where a population of organisms can
         languages evolve over time by adding new color                      evolve in any of a number of directions, subject to the
         categories (see also similar concepts proposed by                   Darwinian principles of natural selection.
         Gladstone, 1858; Rivers, 1901; Hugo Magnus, trans-                     Berlin and Kay’s second conjecture poses two
         lated in Saunders & Marth, 2007; and Schontag &                     important questions pertaining to languages like
         Schafer-Priess, 2007). According to the second con-                 American English, which are spoken in technologically
         jecture, new color terms are continually being added                advanced cultures. First, is the current state of modern
         color naming in these languages a proper end state of         Berlin and Kay were allowed. This constrained-naming
         color-term evolution, as Berlin and Kay proposed?             phase of the protocol was used to establish each
         There is some evidence that it is not. First, several         informant’s BCT category boundaries. Then, the
         modern languages with more than 11 basic color terms          deployment of nonbasic color names—within versus
         have been identified, which otherwise satisfy Berlin and       between BCT categories—in the free-naming phase
         Kay’s criteria. These include Russian (Davies &               could be gauged in relation to these boundaries.
         Corbett, 1994; Winawer, 2007), Greek (Thierry et al.,            The data analysis in the present project followed the
         2009), and Turkish (Ozgen & Davies, 1998). Second,            two-stage cluster-analysis methodology of Lindsey
         there is some evidence that other English-like color          and Brown (2006, 2009). In the first stage, each color
         lexicons may be continuing to evolve. For example,            term used by each informant was encoded by a
         Zollinger (1984) proposed that turquoise may be a             separate binary feature vector, which represented the
         nascent color category in German, and Boynton and             subset of color samples associated with each color
         Olson (1987) proposed that even English itself might be       word. These feature vectors were then partitioned into
         currently evolving, adding peach as a possible new            distinct clusters, which represented a glossary of
         color category.                                               distinct color categories identified in the data set
            The second question arises if we grant the likelihood      irrespective of the actual words associated with the
         of the continuing evolution of the English color              clustered feature vectors. This step avoided the
         vocabularies: How are the new categories formed? Is           potential pitfalls of synonymy in the data analysis. In
         the process constrained by the partition principle of         the second stage, the clustered feature vectors were
         Kay et al., or by some other process? An alternative          used to reconstruct a representation of the glossed
         process has been advanced by Levinson (2000) and              color-naming system for each American English–
         Lyons (1995), who have challenged both of Berlin and          speaking informant, and a second cluster analysis of
         Kay’s conjectures. Here, we focus on the second               the data set was performed at the level of the
         conjecture and Levinson’s idea that in the earliest
                                                                       informants. This step allowed us to determine whether
         stages of color-term evolution, color vocabularies do
                                                                       distinct subpopulations of American English–speak-
         not exhaustively name all colors. Rather, according to
                                                                       ing informants express different color-naming motifs.
         Levinson, each ancient color term referred to a
                                                                       This two-stage cluster analysis permitted an analysis
         restricted range of colors that were identified with a
                                                                       of the American English color lexicon that was more
         particular item in the environment, for example a
         certain animal or plant, or a substance such as blood or      nuanced and powerful than one based on simple
         bile. Over time, the original terms generalized to the        tabulation of subject color-naming responses.
         colors of the substances to which they originally                This analysis was designed to address the issues
         referred. However, great gaps remained where the              outlined previously. Under the first conjecture, are
         colors were either unnamed or else were named with            there color terms in American English that fulfill
         great difficulty. According to Levinson, additional            Berlin and Kay’s definition of the BCTs? And are the
         color terms came into use as the need arose to name           most common American English color terms equiva-
         colors in the gaps, colors that previously had no names.      lent to the universal color terms that have previously
         Thus, according to Levinson, ‘‘color terms [emerge] out       been identified for the WCS, or do they differ from
         of noncoloric expressions’’ (2000, p. 8); this view of        those universal terms in important ways? Under the
         color-term evolution has come to be known as the              second conjecture, is American English in the process
         ‘‘emergence hypothesis.’’                                     of evolving to higher numbers of BCTs, as suggested
                                                                       by Boynton and Olson? And if new color terms are
                                                                       evolving in American English, do they appear by
         This project                                                  partitioning existing categories into smaller ones, as
                                                                       Kay et al. proposed? Or is Levinson closer to the
            In the present study, we examined Berlin and Kay’s         mark, with these new terms appearing de novo,
         two conjectures in light of a new color-naming data set       popping up in places where no high-consensus color
         that we obtained from American English–speaking               term exists and informants find the colors hard to
         informants. To facilitate comparisons between Amer-           name? Finally, we used the data set to examine the
         ican English and the 110 languages represented in the         relationship between informant gender and color
         World Color Survey, we used the set of Munsell color          naming. Several studies have proposed that females
         samples used in the WCS. We used a ‘‘free-naming’’            have larger color vocabularies than males, possibly for
         protocol, in which informants used whatever single            genetic reasons, and women might have a finer
         color term they wished, subject to a few simple rules,        appreciation of the differences between colors and
         and we added a ‘‘constrained-naming’’ phase to the            their identities because of their roles in modern and
         data-collection protocol, in which only the 11 BCTs of        traditional cultures.
            This data set also allowed us to examine prospectively        (Kay et al., 2010). Ten samples were achromatic, with
         the generality and replicability of the motifs of Lindsey        values from 1.5/ to 9.5/ in the notation of the Munsell
         and Brown (2009). Their conclusion that multiple motifs          color-order system. The remaining samples were the 40
         exist side by side within the lexicons of most world             equally spaced Munsell hues (2.5 R to 10 RP, in hue
         languages was based on an analysis of the WCS, a data            steps of 2.5) sampled at each of eight values from 2/ to
         set that had already been collected. This unexpected             9/ (hence, 320 hue/value combinations). The chromatic
         result suggested that the color lexicons of many world           samples generally had high chroma, except for some
         languages are currently undergoing linguistic change,            hues at the lowest and highest values, where the
         albeit over more trajectories than the simple path               Munsell Book of Color does not contain high-chroma
         originally proposed by Berlin and Kay. Therefore, it was         samples. Each sample was placed in a 51-mm · 28-mm
         important to determine whether multiple motifs occur in          holder, which was covered in Color-aid N4.5 paper
         a data set that was collected to reveal them if they exist.      exposing a 20-mm · 20-mm (2.38 · 2.48 at an
         On one hand, American English is a written language              approximate viewing distance of 500 mm) portion of its
         spoken by a large number of people, which suggests that          Munsell sample.
         it might not still be evolving in a basic, common lexicon
         such as the names of colors. On the other hand,
         American culture is highly industrialized, which suggests        Apparatus
         that there might be a need for more color terms as more
         and more artifacts in American culture differ from one              The color samples were presented in a custom-made
         another only in their color.                                     light box, with white walls, a floor covered with Color-
                                                                          aid N 4.5 paper, and a 42-cm · 142-cm opening
                                                                          through which subjects viewed the illuminated color
          Methods                                                         samples. Illumination was provided by a bank of four
                                                                          full-spectrum fluorescent lights (F40T12 Spectralite;
                                                                          CRI 90) suspended from the top of the light box. Color
         Informants                                                       calibrations were performed using a PhotoResearch
                                                                          PR-670 spectrophotometer at regular intervals
            Fifty-one native American English–speaking infor-             throughout the duration of the study. Illumination
         mants (24 men and 27 women; ages 19–58 years)                    varied between 1970 and 2216 lux during the course of
         participated in the study. All were born and raised in           the study and had a correlated color temperature
         the United States, none had spoken any language other            (CCT) of between 5200 and 5400 K during the same
         than English at home before the age of 12 years, and all         time period. This CCT is near that of direct sunlight.
         resided in the Columbus, Ohio, metropolitan area at
         the time of testing. None of the informants were aware
         of the hypotheses being tested in this study. All subjects       Procedure
         reported that they were free of visual pathology except
         for refractive error, and all were color normal, as                 At the beginning of each experimental session, the
         assessed using the D-15 screening test. The informants           informant was briefed on the nature of the task. After
         were tested following a protocol previously approved             the informant provided informed consent for partici-
         by the Ohio State University’s Institutional Review              pation in accordance with the Declaration of Helsinki
         Board, and all gave informed consent prior to                    and under the approval of the Ohio State University
         participating in this study.                                     Institutional Review Board, we obtained the infor-
            Data on three additional male informants, one who             mant’s age and sex, the languages he or she spoke and
         spoke British English and two who were color-vision              at what age he or she learned them, where he or she was
         specialists and well aware of the hypotheses being               born and lived as a child, and where he or she lived
         tested in this study, have been eliminated from the data         presently. We also administered the D-15 panel to
         set reported here. None of the results or conclusions            screen for color-vision deficiency.
         from this project are materially affected by the                    The color-naming part of the experiment consisted
         exclusion of these informants.                                   of two phases: free naming and constrained naming.
                                                                          The free-naming phase of the experiment was always
                                                                          completed first, and informants were not apprised of
         Color samples                                                    the second, constrained-naming, phase until after the
                                                                          first phase was completed. All but one informant
            The 330 color samples were taken from the Munsell             completed both color-naming phases in one 1.5-hr
         Book of Color Glossy Edition and corresponded closely            experimental session. The remaining informant re-
         to those used in the World Color Survey color chart              quired two 1.5-hr sessions to complete the two color-
         naming phases of this study. Subjects were paid with a         required the informant to provide a BCT from the list.
         $10 gift card for their participation.                         The colors provided in the constrained-naming phase
           In the free-naming phase of the experiment, the              were added to the data set obtained in the free-naming
         experimenter presented each of the 330 Munsell                 phase to create a second complete constrained-naming
         samples in the light box in a fixed, pseudorandom               data set.
         order. The subject named each color sample in turn.
         The instructions were to name the colors of the
         samples, based on the following three criteria:
                                                                         Results
         1. The color name must be a single word. (Phrases like
            light blue and dark green, and phrases with intrinsic
            modifiers like yellowish are not acceptable.)                Color terms elicited under free-naming
         2. The word must be a general color name, applicable           instructions
            to anything of that color. (Blond, for example, is not
            such a word, as it is used to name the color of hair,          Every informant succeeded in naming every sample
            furniture, or beer, but not, for example, a car or a        with a monolexemic color term in the free-naming
            potato.)                                                    phase of the study. The 51 native American English–
         3. The word must be the one that you would normally            speaking informants used a total of 122 color terms to
            use to name the color of something in your everyday         name the 330 Munsell samples (Tables 1 and 2). Figure
            life. (We are not looking for a unique name for each        2a and Table 3a present the most commonly used basic
            color. We are not testing for how many different            and nonbasic color terms in this study. The mean
            color names you know or can dream up, or how                number of free-naming color terms per informant was
            many subtle distinctions in color you can name. We          21.9 (SD ¼ 7.6) and the minimum number of color
            want just to know how you naturally name the                terms was 12 (Figure 3a).
            colors, when you can use only a one-word name.)                Among the nonbasic terms, peach was used by the
                                                                        largest number of informants (40 out of 51 informants).
            Once we had instructed the informant and answered           Teal, which was used by 32 of 51 informants, was the
         any questions, the informant was allowed to use                only other nonbasic term used by over half of
         whatever color terms he or she chose: Informants               informants. Fifty-nine of the 122 color terms (48.4%)
         complied with criterion #1 without exception, and we           were used by only one informant each, and of those, 25
         did not interrupt to object to terms that might have           were used only a single male informant. The inventory
         violated criteria #2 or #3. Color terms that were not          of frequently used nonbasic color terms in Figure 2a
         among the 11 BCTs of Berlin and Kay were flagged on             and Table 3a is qualitatively similar to that reported by
         the data sheet. The free-naming data set was the full set      Boynton and Olson (1987, 1990) and by Sturges and
         of monolexemic color terms provided by this sample of          Whitfield (1995). However, none of those previous
         informants.                                                    studies mentions teal in its nonbasic color inventory;
            The instructions in the free-naming phase of data           instead, they all report the use of turquoise, which we
         collection differed somewhat from those used in the            found to be synonymous with teal (we deal with color-
         WCS protocol. In that study, field-workers were                 term synonymy later). None of Sturges and Whitfield’s
         encouraged to elicit short, single-word BCTs from their        informants used lavender, though they did report the
         informants, in their native language. However, there           term lilac, which we found to be synonymous with
         was probably considerable variation in how these               lavender. Finally, Boynton and Olson (1990) reported
         instructions were actually followed by field-workers            that both peach and tan were used by all nine of their
         (see Cook, Kay, & Regier, 2005). Thus, we believe our          informants, compared to 62.7% and 45.1%, respec-
         color-naming protocol adhered reasonably well to that          tively, of informants in this study. Boynton and Olson
         of the WCS as actually implemented in the field.                (1987, 1990) speculated that peach might be an
         Moreover, by using a relatively unconstrained color-           emerging 12th English BCT. We will return to this
         naming protocol in the first phase of data collection, we       point in the Discussion section of this article.
         could compare our results to those of prior studies of            While every informant used all the BCTs of Berlin
         English monolexemic color naming by Boynton and                and Kay, the BCTs differed considerably in their
         Olson (1987, 1990) and by Sturges and Whitfield (1995,          frequency of usage (Table 3a). On average, 24.0% of
         1997).                                                         the sample presentations (4,035 of 16,830 total re-
            In the constrained-naming phase of the experiment,          sponses) elicited green as a color term, followed by blue
         we gave the informant a printed list of the 11 BCTs. We        (16.9%). Red, with a usage rate of 3.3%, was the least
         then presented, for a second time and in reverse order,        elicited of the chromatic BCTs. Of the neutrals, black
         the samples corresponding to the color terms that were         was elicited by 1.9% of the 330 color samples across the
         flagged in the free-naming phase of the experiment, and         51 informants, white was elicited by 4.7%, and gray was
                                                                                                                             Terms/informant
                                           Number of     Number of              Type of          Number of
         Study                             informants   color samples           samples            terms     Mean      SD        Median   I.q.r.*   Mode
         Table 1. Basic data from three studies. Notes: *Interquartile range. **No two subjects used the same number of terms. ***Not
         reported.
         elicited by 2.2%. The nonbasic term used to name the                         Color terms elicited under constrained-naming
         most samples was teal (2.0% of samples), followed by                         instructions
         peach (1.5%) and lavender (1.3%). The only term for
         light blue was sky, which was used by only four                                 Under the constrained color-naming instructions, all
         subjects, to name 0.21% of samples.                                          the informants succeeded in naming all of the samples
             Many investigators have found that the frequency of                      for which they had provided nonbasic color terms in
         word use conforms to a power law—that is, the                                the free-naming part of the protocol. This was
         logarithms of the frequency with which words occur fall
         on a line when graphed as a function of the logarithm of
         their rank order. This power-law relation is sometimes
         called Zipf’s law (see Mitzenmacher, 2003, for a review).
         Contrary to that general result, when we graphed the
         number of informants using each term (the term’s
         ‘‘popularity’’) as a function of the sorted rank order of
         that term’s popularity (Figure 4, lower data set), the data
         were broken quite sharply into three regimes. First, there
         was a ceiling effect, as the BCTs were all used by all 51
         informants and are therefore fitted perfectly by a constant
         function. For the next 17 most popular terms, the power
         law had an exponent of 1.2, whereas the power law for
         the less popular terms was 3.32 (gray circles in Figure 4).
         The slopes of these functions depended somewhat on how
         ties were treated in the rank ordering (here, tied
         frequencies have consecutive ranks) and how the BCTs
         were shown on the graph (here, included as 11 tied
         frequencies). However, no matter how we treated the ties,
         there was always a break in the function after the 28th
         term (11 BCTs plus 17 additional popular terms; numbers
         listed in Table 2; colors listed in Table 3a). Double-power-
         law behavior is common in language corpora, where two
         exponents often ‘‘divide words in two different sets: a
         kernel lexicon formed by about N versatile words and an
         unlimited lexicon for specific communication’’ (Ferrer i
         Cancho & Solé, 2001, p. 170).
         Criterion                                      All Chromatic Nonbasic
         Used by . 0 informants                122            122         111
         Used by . 1 informant                  63             63          52
         Used by . 2 informants                 51             51          40
         Used by . 3 informants                 43             43          32
         Basic color terms (Berlin & Kay, 1969) 11              8           0
         Most common color terms*               28             25          17         Figure 2. Histograms of color-term usage in the free-naming
         Glossed color categories**             20             17           9         phase of the experiment. (a) The number of informants using
                                                                                      each of the 43 color terms used by four or more informants. (b)
         Table 2. Free-naming color terms. Notes: *White disks in Figure              The free-naming data consolidated by cluster analysis into
         4. **See Figures 2b and 3b and Table 3.                                      glossed categories.
                                                      Number of Number of
                                            Rank by informants     samples
                                           popularity (popularity) (usage)
         Figure 5. Diagrams of color-naming consensus in the free-naming (a–c) and constrained-naming (d–f) tasks. See text for details of
         color coding. (a, d) Consensus maps of the usage of the BCTs of Berlin and Kay (1969). Second and third rows indicate samples for
         which the consensus reached or exceeded two threshold criteria: 1.0 (b, e) and 0.8 (c, f). Red dots: focal colors from Berlin and Kay
         (1969); orange dots: focal colors from Sturges and Whitfield (1995).
            In Figure 5b, c, e, and f, the data from Figure 5a          was defined as the average coordinates of the samples
         and d were examined by applying two threshold levels           that were named with the corresponding term by one
         of consensus: 1.00 (Figure 5b, e) and 0.80 (Figure 5c, f;      subject, specified within the 2-D Cartesian coordinate
         0.80 was one of the criterion levels used by Kay et al.,       frame of the color chart shown in Figure 1. The faint
         2010, in their description of the World Color Survey           colors in the backgrounds of Figure 6a through d are
         data set]. In those diagrams, the chromatic color              the false colors from Figure 3f, corresponding to the
         categories named at or above the critical value of             modal BCTs used at consensus  0.80. Here, we
         consensus appear as islands of at-or-above-threshold           provide this map as a guide for examining the color-
         agreement, separated by black boundary regions of              term centroids. The black dots in Figure 6a are the
         below-threshold agreement. Agreement among sub-                averages of the centroids across all 51 subjects. For
         jects was perfect (consensus ¼ 1.0) for 6.3% of samples        comparison, the white dots are the average centroids
         in the free-naming data set and for 31% of samples in          obtained from 20 University of Teesside (U.K.)
         the constrained-naming data set. Fifty-two percent of          undergraduates by Sturges and Whitfield (1995),
         the samples in the free-naming data set and 69% of the         whose 446 Munsell color samples spanned a greater
         samples in the constrained-naming data set reached or          range of chromas than were used in the present
         exceeded a consensus criterion of 0.80. In the free-           study. The centroids from the two studies agree fairly
         naming data set, none of the samples were called               well.
         white, red, yellow, pink, or orange by all informants,            A striking feature of the individual data is the
         and even in the constrained-naming data set, no                informant-to-informant variation in the usage of the
         samples were called white or red by all informants.            nonbasic color terms. Informants often used different
         However, at the 0.80 consensus threshold, all the              color names to label similar regions of color space.
         BCTs were represented in both the free-naming and              For example, in the central region of the color chart
         constrained-naming data sets. The dots in Figure 5 are
                                                                        (Figure 6b), there were seven different nonbasic color
         the ‘‘focal colors’’ of Berlin and Kay (1969) and
                                                                        terms: teal, turquoise, aquamarine, aqua, jade, ocean,
         Sturges and Whitfield (1995), that is, the colors that
                                                                        and seafoam. These terms reliably denoted colors that
         were chosen by their informants to be the best
                                                                        fall near the boundary between the blue and green
         examples of each of the color categories. The focal
                                                                        BCT categories, and the distributions of the centroids
         colors correspond closely to the regions of high color-
         naming agreement, which indicates that color samples           for these seven terms were broad and showed
         were named with high consensus if they were, on                considerable overlap. However, the centroids were
         average, particularly good examples of named color             not quite identical, suggesting that informants might
         categories. Conversely, as colors deviated more and            differ slightly in the meanings they associate with
         more in appearance from the focal colors, subjects             these nearly synonymous color terms. The centroids
         were more variable in their responses and consensus            for maroon and burgundy showed almost perfect
         agreement declined.                                            overlap, and the centroids for lavender and lilac also
            The features of the 0.80 threshold consensus map for        overlapped greatly within the upper lightness range
         the constrained-naming task generally agree with the           of samples called purple on the constrained-naming
         results of prior studies of English color naming by            task. The centroids for violet, like those for teal,
         other investigators (Boynton & Olson, 1987, 1990;              covered a large range of lightnesses, suggesting that
         Sturges & Whitfield, 1995). Green and blue were the             violet was generally not synonymous with lavender
         only named categories that extended vertically                 and lilac.
         throughout the lightness range. All the other basic               In contrast, some color terms were used to name
         color categories were confined to restricted ranges of          quite different colors by different individual infor-
         lightness: Pinks and yellows were light compared to the        mants. For example, the centroids for tan (Figure 6b)
         neutral background against which the colors were               appeared in two disjoint areas of the color diagram:
         viewed, and reds and browns appeared among the                 One area overlapped with the centroids for peach and
         lower lightness warm colors; orange was at an                  beige, and the other was close to the centroids for olive.
         intermediate lightness value.                                  Similarly, informants used chartreuse to mean either
                                                                        greenish-yellow or desaturated green (synonymous with
                                                                        lime). Puce is also interesting, as all three of the
         Color-term centroids                                           informants who used this term applied it to yellowish-
                                                                        green-colored samples. Apparently informants using
           To examine the individual data, we calculated the            puce did not know that it refers to a dark, highly
         color-term centroids for each term for each infor-             saturated purplish red or purplish-brown, and they
         mant from the free-naming phase of the study                   assigned the color term instead to the color of vomit
         (Figure 6). Each centroid (shown by the colored dots)          (purple dots in Figure 6b).
         The nonbasic color terms: Partition or boundary                disks in Figure 4; see Table 2) fall into the overlap
         colors?                                                        region between 1 and 1.5 chips; the average distances
                                                                        for the other colors were all cleanly divided between the
            These data sets allowed us to examine the second            BCTs, which were centered in their BCT categories,
         conjecture and the two hypotheses about the origins of         and the nonbasic color terms, which appeared at the
         new color categories: the partition hypothesis of Kay et       boundaries of the color terms. The three nonbasic
         al. and the emergence hypothesis of Levinson. We               terms that fell in the overlap region were lavender, lilac,
         examined the locations of the centroids of the color-          and lime. The average distance between the BCTs and
         naming patterns in the free-naming data set relative to        their nearest color boundary was 1.78 chips (SD ¼
         the boundaries of the BCTs obtained from the                   0.89); for the nonbasic color terms it was 0.65 chip (SD
         constrained-naming data. If the partition hypothesis is        ¼ 0.34), a statistically significant difference: t(7) ¼ 3.50,
         correct, then each nonbasic color term will tend to be         df ¼ 8, p ¼ 0.008.
         located within one of the BCT categories, with its                In summary, the nonbasic color terms generally
         centroid at some distance from the nearest BCT                 appeared at the boundaries between the BCT catego-
         boundary. In contrast, if the emergence hypothesis is          ries. This result was broadly in agreement with
         correct, and new terms intrude into the areas between          Levinson’s emergence hypothesis. However, the color
         named categories, then the centroids for the nonbasic          terms for light purple (lavender and lilac) and light and
         color terms will be located near the nearest BCT               dark yellowish-green (lime and olive) appear to be
         boundary, and the average distance to the nearest              partition colors in the sense of Kay et al. These results
         boundary will be near zero.                                    show that both processes can occur, although the
            For each color-naming pattern for each informant,           intrusion of new colors in between established catego-
         we calculated the unsigned distance between its                ries may be more frequent in modern American
         centroid and the nearest BCT boundary, expressed as            English. Previous work by Sturges and Whitfield (1997)
         the number of samples between the centroid and the             has suggested qualitatively that British English might
         closest boundary (above, below, to the right, or to the        also have more intrusion colors than partition colors.
         left of the centroid). Inasmuch as the centroids were not
         integers, the separation between the centroids and the
         boundaries were not integers either. Figure 7 shows the        American English glosses
         results of this analysis in two ways. In the line graphs,
         the distance data from the informants who used a given            Inspection of the list of color terms from the free-
         color term were binned into half-chip bins. Each line          naming phase of the experiment (Table 3a), and
         shows, for a given color term, the number of                   examination of the individual data outlined previously,
         informants who placed it within 0.5 chips of the nearest       suggested that many of the terms that subjects used
         boundary, between 0.5 and 1 chip from the nearest              might be synonyms. Perhaps the very large number of
         boundary, and so forth. Not surprisingly, the centroids        color terms shown in Figures 2a and 3a would be much
         of the BCTs were well centered within their respective         smaller if those synonym groups were to be consoli-
         categories (Figure 7a; see also Figure 6a), so the             dated into larger color categories, much as Lindsey and
         distances to their nearest boundaries were generally           Brown (2006) did in their cluster analysis of the WCS.
         greater than 1 chip. The closest bin (under 0.5-chip           Therefore, we applied a similar k-means analysis to the
         separation) was never the most frequent separation             present data set. Briefly, we expressed each chromatic
         between a BCT centroid and its nearest boundary. In            color term (i.e., each term not used to name any of the
         contrast, the distance data for 13 of the 17 most              10 achromatic color samples in the WCS chart)
         frequently used nonbasic chromatic colors were at their        deployed by each of the 51 informants as a 320-element
         maximum within 1 chip of zero, as predicted by the             binary feature vector, representing the 320 chromatic
         emergence hypothesis. Figure 7b shows the results for          color samples in the WCS chart. For a given color term
         four representative nonbasic chromatic color terms.            (say, yellow) used by a particular informant, each
         However, the distance data of four of the 17 most              element of the term’s feature vector was assigned the
         common nonbasic terms peaked at a distance of more             value 1 if that informant called the corresponding
         than 1 chip. These were lavender, lilac, olive, and lime       chromatic sample yellow and 0 otherwise. Applying this
         (Figure 7c; compare to Figure 6c, arrows).                     encoding to all of the chromatic words used by our
            The bar graph (Figure 7d) shows the average of the          informants yielded a total of 963 binary feature vectors.
         unsigned nearest boundary distances for each color             We then performed a k-means cluster analysis,
         term. The average distances for the BCTs and the               computing a partition of the feature vectors into k ¼ 2
         nonbasic chromatic color terms overlap only slightly:          clusters, then k ¼ 3, then k ¼ 4, and so forth. The k-
         Seven of the 25 most frequently used chromatic color           means process works by assigning each feature vector
         terms (the chromatic color terms shown with the white          to the ‘‘nearest’’ cluster in feature space. We used a
         Figure 6. Centroids of named color categories provided by individual informants in the free-naming task. (a) Centroids of the 11 BCTs
         of Berlin and Kay (1969), with the group average centroids (black disks) and the centroids of Sturges and Whitfield (1995; white disks).
         Color key for the chromatic color terms is above and below the diagram. (b) Individual differences in usage of nonbasic color terms.
         The centroids for tan are disjointly distributed in the warm-color region of the chart. Informants used several terms—some of which
                                                                                                                                              
         were uncommon—in the area between the green and blue BCTs: teal, turquoise, aquamarine, aqua, jade, ocean, and seafoam. The dark
         purplish centroids within the green region (arrow) are for the color puce. (c) Centroids of the 17 most common color terms (Figure 4,
         Tables 2 and 3a). Most nonbasic color terms in the free-naming task fall near the boundaries between the BCTs, where consensus for
         the BCTs is low. However, lime and olive and lavender and lilac (arrows) are generally proper subsets of green and purple, respectively.
         Color key for (b) and (c) is below (c), and the asterisks refer to the centroids indicated with arrows. (d) Informants used color terms
         for the light colors peach, yellow, lime, lavender, and pink, but not for light blue. Color key above the diagram.
         j feature vectors drawn from the uniform reference               of kopt. The minimum value of kopt was 11, so there
         distribution:                                                    were always at least three more clusters in the data set
                                                                      than the eight chromatic BCTs listed by Berlin and
              gðkÞ ¼ log TDRn ðkÞ  log TDDðkÞ              ð1Þ           Kay. The mode of the kopt distribution (which was
                                                                          close to its median and its mean) at kopt ¼ 17 was the
            The gap statistic is based on the intuition that if a         best estimate of the statistically significant chromatic
         data set contains exactly kopt clusters, then g(k) will          clusters in the free-naming data set.
         increase for k  kopt, since k-means is doing an                    Thus, the first cluster analysis of the free-naming data
         increasingly better job of reducing within-cluster               yielded a glossary of 20 color categories (17 chromatic
         distances in the data set as k approaches kopt when              color categories plus black, white, and gray; Table 2).
         compared to the distances obtained by clusterings of             This glossary included nine more chromatic clusters in
         the reference sets, which by design have no clusters. For        the free-naming data set than there are BCTs, according
         k . kopt, the partitions must split one or more of the           to the first conjecture of Berlin and Kay. All informants
         kopt clusters, and g(k) will not continue to improve and         used more than 11 glossed color categories; the most
         may even decline relative to g(kopt).                            frequent number was 18 (Figure 3b).
            Let G(k) represent the change in gap between the kth             Consensus diagrams of the 17 chromatic color
         and the kth þ1 clustering,                                       terms appear in Figure 9. In this article, we call them
               GðkÞ ¼ gðk þ 1Þ  gðkÞ  sTDR ðk þ 1Þ;           ð2Þ       by the names most commonly used by informants
                                                                          (above each diagram in Figure 9; see also Figure 2b).
         where sTDR(k þ 1) is an error term related to the                The second result was that even when all the colors
         standard deviation of the log TDRn(k). Then kopt is              were consolidated into their kopt clusters, none of the
         defined as the largest k before the first zero crossing of         nine statistically significant nonbasic chromatic cate-
         G(k) (see Tibshirani et al., 2001, for details). Formally,       gories was used by 100% of informants (Table 3b,
         this rule is stated as follows:                                  categories of rank 12–20). The clusters illustrated in
               kopt ¼ argmaxfkjGðkÞ . 0g:                       ð3Þ       Figure 9 were used in the motifs analysis described
                             k                                            later in this article.
            Among the virtues of the gap statistic is that it can            The glossary derived from the k ¼ 17 solution varied
         test for the absence of any clusters in the data set (i.e.,      slightly from run to run. Repeated runs of k-means
         kopt ¼ 1).                                                       revealed essentially the same glossary, but occasionally
            Our gap-statistic analysis was based on n ¼ 20                the lime cluster shown in Figure 9 was replaced by a
         reference sets. To create a reference set, we took the 963       rust (dark red) category. Most k-means runs produced
         color-naming patterns from our data set. The centroid            cluster centroids that were all confined to contiguous
         of each pattern was then randomly relocated to a new             regions of feature space, like those illustrated in Figure
         location in the coordinate frame of our WCS color-               9. Occasionally, however, one of the 17 consensus maps
         sample space, and a feature vector for this new pattern          derived from cluster analysis covered two disjoint
         was created based on the new location. Thus, our                 regions of the color chart. One of the regions was
         reference sets preserved exactly the distributions of the        always more prominently represented than the other,
         sizes and shapes of regions of color space associated            and the corresponding cluster centroids were easily
         with the color terms observed in the original data set.          associated with one of the observed nonbasic color
         However, in each reference set, the locations of the             terms. In any event, the minor run-to-run perturbations
         centroids of the feature vectors were drawn from a               in the k-means derivation of the American English
         uniform distribution of centroids falling within the             glossary did not affect the main conclusions drawn
         coordinate frame of the WCS color chart, and therefore           from the motifs analysis discussed later.
         had no natural clusters.
            Preliminary studies indicated that despite adopting a
         best-of-100-replications criterion for the clustering of         American English motifs
         our data, several independent clusterings of the data for
         a given value of k still tended to produce small                    In their analysis of the WCS data set, Lindsey and
         differences in TDD(k). In order to assess the impact of          Brown (2009) found that the color-naming systems of
         this variation on our gap-statistic analysis, we ran 1,000       individual informants around the world fell into about
         separate analyses. For each analysis, we created k-              four motifs, and that multiple motifs were present in the
         means clusterings of the data for k ¼ 1, . . ., 25 and           data sets of the great majority of the WCS languages. To
         compared those to the corresponding clusterings on a             determine whether these results also apply to American
         new ensemble of 20 reference sets.                               English, we performed a second k-means analysis on the
            Figure 8 shows the values of the gap statistic G(k)           present data set, based on the glossary of 20 terms
         over the 1,000 runs, and the inset shows the distribution        revealed by the first k-means analysis.
Figure 9. Consensus diagrams of the 17 chromatic color terms identified by the first k-means cluster analysis.
         Figure 10. The results of the second cluster analysis, based on the glossed color-naming patterns from the free-naming task. (a–b)
         Seventy-three percent of 51 informants fell into a cluster that corresponded closely to the green–blue motif of Lindsey and Brown
         (2009). This motif is similar to the Stage-VII pattern of Berlin and Kay (1969), being composed primarily of the 11 BCTs. (a) Consensus
         map. (b) 0.8 threshold consensus map. (c–d) The remaining 27% of 51 informants fell into a second, green–teal–blue motif, which is
         new here. The new motif included the high-consensus nonbasic terms maroon, peach, teal, and lavender. These new colors (see
         arrows) appear in both the consensus map (c) and the 0.8 threshold consensus map (d).
         BCTs of Berlin and Kay (plus black, white, and gray).                 performed a separate analysis employing 330 element
         Thus, the first motif is similar to the green–blue (GB)                vectors, where each element was assigned a nominal
         motif in the WCS, which was so-named after the color                  value representing one of the 20 glossed terms. In this
         terms corresponding to the cool colors (Lindsey &                     approach, which Lindsey and Brown (2009) used in their
         Brown, 2009). Informants expressing this motif tended                 analysis of the WCS motifs, the dissimilarity metric was
         to use the nonbasic color terms in the glossary                       a modified Jaccard coefficient (Leisch, 2006). In yet
         idiosyncratically and with low frequencies. The infor-                another version of the motif analysis, the 20-element
         mants whose data fell into the second motif also used the             feature vectors were populated with z scores representing
         11 BCTs of Berlin and Kay, but they also used some                    deviations of each informant’s usage of each glossed
         additional terms extensively and consistently, particu-               term from the mean. The most striking result was that
         larly teal, peach, lavender, and maroon. Figure 10d shows             all these approaches agreed very well on the identity of
         that consensus for each of these terms equaled or                     the first two motifs: a green–blue motif and a second
         exceeded 0.8 for some of the color samples. We will call              motif—green–teal–blue—with high informant usage of
         this the green–teal–blue (GTB) motif because of the                   teal, peach, maroon, and lavender. Beyond two motifs,
         names given to the cool colors. The GTB motif is new,                 the various cluster analyses mostly generated minor
         and did not appear in the WCS analysis. Fourteen                      variations on the green–blue motif and variations of the
         informants used the GTB motif, whereas 37 informants                  green–teal–blue motif that emphasized various subsets
         used the GB motif. Partition of informants’ data into the             of the four additional categories in the green–teal–blue
         GB and GTB motifs increased color-naming consensus                    motif. The main differences between the various
         from the overall value 0.74 for the free-naming data set              approaches were in their statistical power. The 330-
         as a whole to an average within-motif consensus of 0.79               dimension approach revealed only one statistically
         for the glossed terms (GB consensus ¼ 0.81, GTB                       significant motif, whereas the 20-dimension approach
         consensus ¼ 0.77). We created 10,000 partitions of the                involving z scores revealed four statistically significant
         informants’ data into two random ‘‘motifs’’ with 37                   motifs. The 330-dimension approach from Lindsey and
         individuals in one and 14 individuals in the other. The               Brown (2009) worked on the WCS data set because of
         highest average consensus from this simulation was 0.77.              the enormous number of observations, where statistical
         Therefore, the statistical significance of our k-means-                power was not an issue. However, that approach was
         based partition is p , 104.                                          apparently underpowered for the present application.
            The results shown in Figure 10 were remarkably                        Figure 10c and d also reveals that three of the four
         robust, as they were essentially independent of the                   high-consensus nonbasic color terms appear in the low-
         precise representation of informant feature vectors that              consensus regions of the chart between the BCTs: Peach
         was chosen, the dissimilarity metric, or even the size of             appears in the dark, low-consensus area between pink,
         the glossary (12  k  22) extracted from the first                    orange, yellow, and white; teal appears between green
         cluster analysis. For example, in addition to the 20-                 and blue; and maroon appears between red and black.
         element informant feature vectors described above, we                 These color terms evidently name new categories that
         arose between categories that previously existed, along          color terms, whereas women used 12.3 nonbasic color
         the lines proposed by Levinson, and were not the result          terms. A multiple regression of the log-transformed
         of partitioning existing color categories into smaller sets.     frequency data (to normalize their distribution) against
         In contrast, the samples called lavender in the free-            age and gender revealed that this difference between men
         naming task were a proper subset of the purple category,         and women was statistically significant (r ¼ 0.304, p ¼
         consistent with the partition hypothesis of Kay et al.           0.0301) but that age was not associated with the number
                                                                          of nonbasic terms (r ¼ 0.079, p . 0.5). Apparently
                                                                          women’s color vocabularies contained more terms than
         The popularity of glossed color terms                            those of men. Women also distinguished more color
                                                                          categories than men did and were more likely to use the
            The number of informants using each of the terms              motif that contained more color terms. In contrast to the
         corresponding to the 20 glossed color categories from            clear effects of gender, this data set showed no
         the first k-means cluster analysis (Table 3b) appears as a        statistically significant age effect.
         function of the rank order of their popularity as the               There is a sizable literature on the subject of
         upper graph (triangles) in Figure 4. As before, the BCTs         gender and color naming (e.g., DuBois, 1939; Now-
         were at the ceiling and were fitted with a constant line.         aczyk, 1982; Simpson & Tarrant, 1991; see Biggam,
         There was a clear break in the function fitted to the             2012, for a recent review), which generally shows
         nonbasic terms no matter how we dealt with ties in rank          larger color vocabularies among women than among
         ordering the data. The four most popular nonbasic                men (but see also Machen, 2002; Sturges & Whitfield,
         terms were fitted with a power law of exponent 0.79              1995). However, data like these do not indicate
         (white triangles), whereas the remaining five terms were          whether this difference is biological or social in
         best fitted with exponent 2.3 (gray triangles). The four         origin. On the biological side, Jameson, Highnote,
         nonbasic categories on the second limb of the function           and Wasserman (2001) have argued that women
         were teal, peach, lavender, and maroon, the same terms           identify more color categories than men do because
         that appeared in the GTB motif. This clear distinction           of well-understood sex-linked genetic differences in
         between the popularity of the four new terms in the GTB          their long- or middle-wavelength-sensitive (L or M)
         motif and the remaining five statistically significant             cone pigments (Nathans, Merbs, Sung, Weitz, &
         terms provides additional evidence, independent of the           Wang, 1992). Many heterozygous females carry the
         second k-means motifs analysis, that those four addi-            genes for four types of cone: In addition to the three
         tional glossed terms are well integrated into the color          normal cone pigments, some have the gene for an
         lexicons of many informants. It also invites the                 additional (normal) L cone pigment, and about 10%
         speculation that the color lexicon of American English is        of females carry the gene for an additional (anoma-
         currently undergoing change, and that those four terms           lous) L or M cone pigment. According to Jameson et
         are in the process of taking their place along with the          al. (2001), women who are heterozygous for the two
         original 11 BCTs of Berlin and Kay.                              versions of the L cone pigment may divide the
                                                                          spectrum into more color bands than men or women
                                                                          with only three cone-pigment genes. However, very
         Gender, age, and color naming                                    few women who are heterozygous for anomalous
                                                                          trichromacy are actually tetrachromats, in the sense
            We also examined the free-naming data set to                  of being able to use the normal and anomalous
         determine whether there was an effect of age and                 pigments together to discriminate between colors
         whether the American men and women in this sample                (Jordan, Deeb, Bosten, & Mollon, 2010), although
         differed in the number of terms in their color                   some apparently experience a subtle influence of their
         vocabularies. Figure 11a shows the number of men and             anomalous cones on color appearance under condi-
         women using each of the nonbasic terms used by three             tions where the influence of the normal cones is
         or more informants. The terms in Figure 11a were                 minimized. Thus, while a well-documented L-cone
         generally used more frequently by women than by men              gene polymorphism might, in principle, provide a
         [average difference ¼ 0.070, t(39) ¼ 2.50, p ¼ 0.017, two-       basis for explaining some or all differences between
         tailed]. When the nonbasic color terms were consoli-             males and females in color naming, the behavioral
         dated into categories, this gender difference persisted          data obtained from heterozygous women do not
         [Figure 11b; average difference ¼ 0.117, t(8) ¼ 2.72, p ¼        provide straightforward, unambiguous support for
         0.027, two-tailed]. Furthermore, men and women were              this explanation. Also on the biological side, there are
         unevenly distributed across the two motifs (Figure 11c),         other biological differences between males and
         with women significantly less likely to use the GB motif,         females, for example due to testosterone receptors in
         and more likely to use the GTB motif, than men: t(49) ¼          the cerebral cortex, that may explain subtle, quanti-
         2.30, p ¼ 0.026. On average, men used 9.71 nonbasic              tative differences between men and women in the
         Figure 11. (a) The fraction of men and women who used each nonbasic color term shown in Figure 2a. Vertical dashed line: the break
         point between the two power-law functions that were fitted to the disks in Figure 4 (Table 2). (b) The pattern of women using more
         color terms persisted when the nonbasic color terms were consolidated into their corresponding glossed color categories. Vertical
         dashed line divides the four nonbasic color terms (to the left of the line) in the second motif from the other nonbasic color terms; it is
         also the break point between the two power-law functions fitted to data in Figure 4 (triangles). (c) The fraction of men and women
         whose data fell into each of the two motifs. GB: the green–blue motif; GTB: the green–teal–blue motif. Error bars: 6 one standard
         error of the dividing line between the two motifs.
         appearance of colors (Abramov, Gordon, Feldman,                        a measurable influence on the appearance and
         & Chavarga, 2012). The present difference between                      naming of colors.
         men and women is probably larger than the subtle                          Some investigators have espoused the alternative
         sex-related differences of color appearance that were                  view that women’s role in society as consumers of the
         reported by Abramov et al. (2012). These two types                     decorative arts has honed their color discrimination
         of biological difference between males and females                     into a finer sense of color appearance, resulting in
         might have small combined effects that together exert                  superior color-category naming ability among women
         than among men (e.g., Rich, 1977; Swaringen, Layman,             categories revealed that their corresponding color
         & Wilson, 1978). The difficulty with the social                   terms were generally deployed to name colors that fell
         hypothesis is that it does not make specific quantitative         in the low-consensus regions between the chromatic
         predictions that could be falsified.                              BCTs of the constrained-naming data set, suggesting
             There is evidence in the field of sociolinguistics that       an ‘‘emergence’’-like mechanism of color-term evolu-
         language change begins with women and young people,              tion. However, two terms, lime and lavender, were
         especially in the lower-middle socioeconomic class, with         proper subsets that partitioned their corresponding
         the language of men, older people, and people of other           BCTs, green and purple, suggesting a ‘‘partition’’-like
         socioeconomic classes changing later (Labov, 1990;               mechanism.
         Tagliamonte & D’Arcy, 2009). The American men and                   A second cluster analysis, based on the glossary
         women in this sample differed in the number of terms in          derived in the first analysis, revealed that this sample
         their color vocabularies, which provides further evidence        of American English–speaking informants expressed
         suggesting that the color lexicon of American English is         two motifs. The first motif, expressed by 73% of
         still changing. However, there was no reliable effect of         informants, was similar to the green–blue (GB) motif
         age. Furthermore, data on socioeconomic status were              observed in the World Color Survey (Lindsey &
         not collected, and our informants probably represented           Brown, 2009). It was also similar to the color lexicon
         a relatively narrow range along this dimension, so               of BCTs listed by Berlin and Kay. The second, green–
         language-change effects related to social class could not        teal–blue (GTB) motif was expressed by 27% of
         be examined.                                                     informants, and included four nonbasic terms that
             It is not immediately clear that the gender difference       were used with high consensus: peach, teal, lavender,
         we report here is directly related to color. In addition to      and maroon. Women were statistically more likely
         the pervasive gender effect outlined by the sociolin-            than men to use the GTB motif.
         guists, Laws (2004) reported other domain-specific                   This prospectively designed study shows that the
         differences in vocabulary size between the genders.              key features of color naming in the WCS are general
         These approaches suggest that the difference in the size         to a written language spoken in the United States.
         of the color lexicons of men and women might be a                These key features are the diversity among the
         specific instance of more general, and less-color-related,        speakers of a single language in how colors are to be
         phenomena. Of course, it is also possible that subtle            named, and the way in which the language’s color
         biological differences between males and females,                terms are deployed across the range of colors that
         combined with the social differences between men and             any individual might encounter. Based on the
         women, are jointly responsible for the reliable gender-          published literature, one might suspect that diversity
         related effect. Such a combined explanation would                across individuals in their color vocabularies might
         require a model with many free parameters, and it                be restricted to unwritten languages such as those in
         would be even harder to test quantitatively than either          the WCS, which are spoken in nonindustrialized
         explanation alone.                                               societies far from Western influence. Contrary to
                                                                          that supposition, prominent diversity in color
                                                                          vocabulary among individuals who speak American
                                                                          English persisted, even after cluster analysis consol-
          Discussion                                                      idated the 122 color terms elicited in a free-naming
                                                                          protocol into a glossary of 20 distinct named color
            The data for this project were the color names                categories. This indicates that diversity among
         provided for 330 Munsell color samples by 51 native              informants is common even in American English.
         speakers of American English under two instructions:             One might also suspect that this apparent within-
         free naming, where any monolexemic color term could              language diversity might be an artifact of each
         be used, and constrained naming, where only the 11               informant’s haphazard color-term choices (from a
         basic color terms (BCTs) of Berlin and Kay (1969)                much larger color idiolect) on the spur of the
         were allowed. This sample of informants used a total             moment, and might not reflect true individual
         of 122 color terms under free-naming instructions,               differences in color cognition. On the contrary, the
         with an average consensus of 0.74, and 11 color terms            diversity reported here was not haphazard: Instead,
         under constrained-naming instructions, with an aver-             there were two distinct motifs, which repeated
         age consensus of 0.85. When the free-naming data set             themselves with minor variation across the idiolects
         was subjected to a cluster analysis similar to that of           of these 51 informants. Thus, the phenomenon of
         Lindsey and Brown (2006), 20 statistically significant            multiple within-language motifs observed in the
         color categories were discovered: the BCTs of Berlin             unwritten languages of the WCS also generalizes to
         and Kay plus nine nonbasic chromatic categories.                 at least one written language spoken in an industri-
         Examination of the centroids of these nine nonbasic              alized society, namely American English.
         The first conjecture of Berlin and Kay: The BCTs                understood to reveal an evolutionary trade-off between
         and their universality                                          the need of the speaker to spend the least effort
                                                                         necessary in communication, at the risk of reduced
            Berlin and Kay’s (1969) first conjecture was that             clarity (producing a small vocabulary), and the need of
         every language includes a vocabulary of no more than            the hearer for conciseness and clarity in the received
         11 BCTs, which are distinct from other ordinary color           message (requiring a larger vocabulary; see Ferrer i
         terms that an informant might use. In English, Berlin           Cancho & Solé, 2003, for further discussion). Double-
         and Kay’s BCTs are black, white, red, yellow, green,            power-law behavior is common and is thought to reflect
         blue, brown, orange, pink, purple, and gray. According          two processes: one process that governs the creation of a
         to Berlin and Kay, the BCTs in any language are                 kernel lexicon of limited size consisting of versatile
         monolexemic, abstract terms that are used by all or             words designed for general but imprecise communica-
         nearly all competent speakers of that language, with            tion, and the other generating an unlimited lexicon for
         high consensus and consistency, to name the color of            specific communication (Ferrer i Cancho & Solé, 2001).
         any type of object, including color samples such as             The unglossed data set shows a break in the function
         those used in the present study. The 11 BCTs of Berlin          between the regimen for the more popular color terms
         and Kay were indeed used by all 51 informants here,             (ranked 12–28) and the less-popular color terms (ranked
         and they were the only terms that showed such full              after 28). This discontinuity may be an instance of this
         usage. This general result is certainly consistent with         distinction between common color terms and those
         Berlin and Kay’s first conjecture.                               chosen on the spur of the moment from a larger color
            However, the free-naming data set shows several              lexicon that each informant has in his or her mind but
         other features that are less obviously consistent with          does not use routinely in everyday communication. Even
         Berlin and Kay’s first conjecture. First, only seven of          the glossed data have a steep-slope section, which occurs
         the BCTs were applied to any samples with 100%                  after four glossed categories. Taken together, the
         consensus, omitting white, red, yellow, pink, and               segmented structure of the frequency data suggested that
         orange (Figure 5b), so the requirement that the 11              the BCTs are not the whole story when it comes to color
         BCTs show high consensus is not perfectly observed.             naming in American English: Even after consolidating
         Second, every informant used at least 12 terms, and             the data into glossed categories, at least four more
         the modal number of terms was 18, so the minimum                glossed color categories are commonly used and
         number of terms is greater than 11. A third finding              understood by many informants.
         that challenges Berlin and Kay’s first conjecture is the
         frequency-versus-rank power-law functions derived
         from the popularity data. If the 11 BCTs of Berlin and          The second conjecture: Color-term evolution
         Kay were the only commonly used terms, and if the
         nonbasic terms were entirely idiosyncratic in their use,           Berlin and Kay’s (1969) second conjecture was that
         the power-law functions should fall off very steeply for        color lexicons evolve over time by adding new color
         ranks greater than 11. Instead, both unglossed data             terms. This evolution occurs as societies become
         and glossed data (white disks and triangles, respec-            technologically more complex, and as distinctions
         tively, in Figure 4) fell off with steepness near 1.0 for      among similar colors become more crucial in the
         the first 17 unglossed and the first four glossed                 everyday lives of their individual members. We
         nonbasic terms. The expected precipitous decline                examined this data set to determine whether it provided
         followed (gray disks and triangles in Figure 4). These          evidence in favor of the ‘‘successive differentiation of
         results suggest that there are about 28 common terms            existing categories’’ specifically suggested by Berlin and
         that are used and understood as part of the core color          Kay’s partition hypothesis, against the alternative view,
         vocabulary of American English; after glossing, 20 of           which is Levinson’s emergence hypothesis (2000),
         these terms are statistically significant, and about four        whereby new color terms are added to cover hard-to-
         of them seemed on their way to frequent use. Those              name colors that for one reason or another have
         four glossed terms are the key components of the GTB            become particularly salient.
         motif, which was expressed by 14 of the 51 informants.             The data set reported here is certainly compatible
            The flow of information from informant to listener is         with the view that the color lexicon of American
         important to understanding the use of color terms in            English is currently evolving. For example, the high
         communicating about color. Zipf’s law expresses the             popularity of the four most common nonbasic color
         reciprocal relationship between the frequency of inde-          categories and their inclusion in the second motif
         pendent observations (e.g., the usage of words in a             suggest that those terms are on their way to joining the
         language, the population of cities; in this case, the           BCTs of Berlin and Kay to form a new lexicon of basic
         popularity of color terms) and the rank order of those          terms. However, it is logically impossible for the
         frequencies. In the case of language, Zipf’s law is             number of color categories to continue to increase ad
         infinitum. Yendrikhovskij (2001) proposed that 16                2007), modern Greek ghalazio (Thierry et al., 2009),
         named color categories is on the high end of basic              (some forms of) Spanish celeste (Bolton, 1978, p. 294),
         color-lexicon size, on the basis of his information-            and Farsi asamuni (Friedl, 1979)—as well as some non-
         theoretic analysis of color terminology. Our Zipf’s-law         Indo-European languages—(some forms of) Arabic
         analysis also reveals a steep decrease in color-term            celesti (Al-Rasheed et al., 2011; Borg, 2007), and
         popularity beyond 15 glossed terms (triangles in Figure         Turkish may distinguish dark blue from light blue,
         4). Thus, 15 or 16 terms may be an upper limit on the           lacivert versus mavi (Ozgen & Davies, 1998). Of the
         size of basic color idiolects, at least in the milieu of        common light color terms in English, pink and yellow
         early-21st-century American English.                            are BCTs, peach is an ‘‘emergent’’ color, and lime and
             The difference between the men and the women in             lavender are ‘‘partition’’ terms. Thus, a light blue color
         the present sample also suggests that the language              term could appear either as a partition of blue or as a
         related to color is changing, and that women are in the         boundary term between blue and white. The fact that
         vanguard. However, the lack of a reliable age effect in         no common color term, basic or nonbasic, exists for
         the present data set suggests that the American English         light blue suggests that the ‘‘emergence’’ and ‘‘parti-
         color lexicon is changing slowly compared to the age            tion’’ mechanisms do not necessarily predict, univer-
         range of our sample, and it does not suggest that               sally, which color terms will occur. This case study
         individual informants recapitulate the history of color-        illustrates how little is really understood about how
         lexicon change over their lifetimes. Without historical         color terms are added to the lexicons of world
         data collected using consistent methodology, it is not          languages.
         possible to examine these issues definitively.                      There has been considerable speculation over the
             The results of these analyses provide some evidence         years about what universal processes guide color-term
         for both Levinson’s and Kay et al.’s (2010) views of            evolution. Kay and his colleagues have emphasized the
         color-term evolution. Much as Levinson suggested, 13            importance of universal aspects of the perceptual
         of the 17 frequently used nonbasic color terms (from            representation of color appearance; particularly, Kay et
         Figure 4, listed in Table 2) appeared in the low-               al. (2010) emphasized the salience of the Hering
         consensus regions between the BCTs, and their                   fundamental hue sensations of red, green, blue, and
         centroids were very near the nearest BCT boundaries             yellow, plus black and white, which they supposed to
         (Figures 6 and 7). For example, peach appears in the            have a well-understood physiological basis. While this
         hard-to-name region between orange, pink, white, and            account is at least qualitatively in line with modern
         yellow. In contrast, four of the 17 nonbasic color terms        accounts of human color vision, the physiology
         were clearly ‘‘partition’’ colors, as predicted by Kay et       underlying the Hering sensations remains obscure
         al. (2010). For example, lavender appeared as a proper          (Lindsey & Brown, 2014). Furthermore, this account
         subset of purple, suggesting that it partitions the large,      does not provide any insight into the order in which
         previously undifferentiated purple category into two            color terms should appear as color lexicons change
         smaller, more articulately named units. These results           (however, see Ratliff, 1976). Recent theories that are
         generally suggested that both ‘‘emergence’’ and ‘‘suc-          based on human perception of color differences predict
         cessive differentiation’’ probably occur as American            that color terms should be added in a manner that
         English adds new color terms.                                   optimally partitions color space by minimizing color
             Considering Berlin and Kay’s evolution conjecture,          differences within the new contiguous color categories
         it is instructive to examine the terms for the light            while maximizing color differences between adjacent
         colors. BCTs and nonbasic color terms exist in                  categories (Jameson & D’Andrade, 1987; Regier, Kay,
         American English to name the light colors in much of            & Khetarpal, 2007). The simulations by Regier et al.
         the diagram: pink, peach, yellow, lime, and lavender            (2007) based on this principle resemble Berlin and
         (Figures 6d and 12). In contrast, there is no commonly          Kay’s evolution trajectory of color names up to six
         used, high-consensus word that means light blue (Table          terms, but the authors do not show simulations for
         3a), a finding consistent with Sturges and Whitfield’s            lexicons greater than this number. Therefore, it is not
         (1995) report of nonbasic-term usage by informants of           clear that their simulations will generalize to more than
         British English, and Boynton and Olson’s (1987, 1990)           six terms. Interestingly, the explanation that Boynton
         studies of American English. Sky, the closest term to           and Olson (1987, 1990) give to explain the possible
         light blue, is included in the unglossed data set in            emergence of peach as a new BCT is similar to the
         Figures 2b and 12, but it ranks 43rd in popularity in           optimal partition principle of Regier et al.
         this data set (Table 3a), and does not reach significance           Other accounts of color-term evolution have focused
         in the cluster analysis that created the glosses. In            on the importance of the statistics of color in the
         contrast to English, light blue has been reported to be a       natural environment. Philipona and O’Regan (2006)
         standard (perhaps basic) color term in some Indo-               argued that the red, green, blue, and yellow universal
         European languages—Russian goluboj (Winawer et al.,             color categories extracted from the World Color Survey
         Department of Psychology, the Ohio Lions Eye                      Categorisation in the Cognitive Sciences (pp. 224–
         Research Foundation, and NSF BCS-1152841.                         242). Amsterdam: Elsevier.
                                                                       Davies, I., & Corgett, G. (1994). The basic color terms
         Commercial relationships: none.                                   in Russian. Linguistics, 32, 65–89.
         Corresponding author: Delwin T. Lindsey.
                                                                       DuBois, P. H. (1939). The sex difference on the color-
         Email: lindsey.43@osu.edu.
                                                                           naming test. American Journal of Psychology, 52(3),
         Address: Delwin Lindsey, PhD, Professor of Psychol-
                                                                           380–382.
         ogy, Ohio State University-Mansfield, Mansfield,
         Ohio, USA.                                                    Ferrer i Cancho, R., & Solé, R. V. (2001). Two regimes
                                                                           in the frequency of words and the origins of
                                                                           complex lexicons: Zipf’s law revisited. Journal of
                                                                           Computative Linguistics, 8(3), 165–173.
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