REPORTS

steroids in asthma may be mediated, in part, by 5. M. Shahabuddin, T. Toyoshima, M. Aikawa, D. C. 18. D. C. Webb, A. N. McKenzie, P. S. Foster, J. Biol. Chem.
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proteins, YM-1 and YM-2 (18) and AMCase 8. J. T. Dessens et al., Infect. Immun. 69, 4041 (2001). HL-61904, R01-HL-64242, R01-HL-66571, and P50-
9. A. Herrera-Estrella, I. Chet, EXS 87, 171 (1999). HL-56389) to J.A.E. and grants from NIH and Amer-
(19) in animal models, these studies emphasize ican Lung Association (R01-HL-074095 and Research
10. S. R. Palli, A. Retnakaran, EXS 87, 85 (1999).
the potential importance of chitinases as mediators 11. Materials and methods and selected data are avail- Grant, respectively) to Z.Z. We thank K. Bertier and S.
of Th2 responses. The present studies also suggest able as supporting material on Science Online. Ardito for their excellent secretarial assistance and S.
12. K. D. Spindler, M. Spindler-Barth, S. Sakuda, Arch. Chen for her technical assistance.
that AMCase is a potential therapeutic target that
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DC1
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Materials and Methods
References and Notes (2002).
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Word Learning in a Domestic joined the owner and the dog. Next, the ex-

Downloaded from www.sciencemag.org on June 28, 2007

perimenter instructed the owner to request the

Dog: Evidence for “Fast Mapping” dog to bring two randomly chosen items (one
after the other) from the adjacent room (9).
While Rico searched for the requested item,
Juliane Kaminski, Josep Call, Julia Fischer* he could not see the owner or the experiment-
er. He retrieved a total of 37 out of 40 items
During speech acquisition, children form quick and rough hypotheses about correctly (binomial test, P ⬍ 0.001). This
the meaning of a new word after only a single exposure—a process dubbed experiment showed that Rico indeed knew
“fast mapping.” Here we provide evidence that a border collie, Rico, is able the labels of these items. One may raise the
to fast map. Rico knew the labels of over 200 different items. He inferred objection that the words may in fact consti-
the names of novel items by exclusion learning and correctly retrieved those tute one-word propositions, such as “fetch-
items right away as well as 4 weeks after the initial exposure. Fast mapping the-sock.” However, anecdotal evidence sug-
thus appears to be mediated by general learning and memory mechanisms gests that he indeed understands that the
also found in other animals and not by a language acquisition device that words refer to the objects. For instance, he
is special to humans. can be instructed to put an item into a box or
to bring it to a certain person. More system-
The rate at which most toddlers acquire their The study animal, Rico, is a border collie atic testing will be needed to specify his
vocabulary is astounding: From about 2 years and was born in December 1994. He lives as understanding of entire phrases. In any case,
of age, typical English-speaking children in- a pet with his owners and was reported by the number of labeled objects is substan-
corporate about 10 new words per day into them to know the labels of over 200 items, tially larger than those reported in previous
their vocabulary until they reach an average mostly children’s toys and balls, which he studies with dogs, where subjects were test-
vocabulary size of 60,000 words by the time correctly retrieved upon request. Rico was ed with only three to five objects (10, 11).
they graduate from high school (1). Several first introduced to fetching items when he Rico’s “vocabulary size” is comparable to
studies have shown that children have a set of was 10 months of age, when his owners that of language-trained apes, dolphins, sea
operating principles that guide the task of placed three different items in different loca- lions, and parrots (12).
word learning (2–4 ). However, it remains a tions around the flat and asked the dog for To assess Rico’s ability to fast map, we
matter of debate which of these principles are one of these items. Rico was rewarded with placed a novel item together with seven fa-
unique to language learning and which are food or play if he fetched the correct object. miliar items in an adjacent room (total n ⫽ 8
more general cognitive abilities that may be He was gradually familiarized with an in- items requested in 8 trials). In this so-called
shared with other living creatures. We inves- creasing number of items. Typically, the identification task, we conducted a total of 10
tigated the outer limits of a domestic dog’s owners introduced new items by presenting sessions in which we introduced 10 novel
“word learning”; that is, his ability to acquire them and saying their name two or three items. In the first trial of a session, the owner
the relation between a word and the object times. Rico then got the chance to play with always asked Rico to bring a familiar item,
that this word refers to (the referent). By the new item, and it was subsequently inte- and in the second or third trial asked him to
studying his retrieval behavior with famil- grated into the collection of other items. bring an item using the novel name (9). After
iar and novel items, we specifically tested However, it remained unclear whether a the completion of a session, Rico was al-
whether he would be able to infer the ref- “Clever Hans” (8) effect might account for lowed to take a break before another session
erent of a new word by exclusion learning: his performance. The first experiment was commenced. Rico retrieved the novel item
that is, to “fast map” (5–7 ) and retain this therefore designed to assess Rico’s ability to from the first session on and was overall
knowledge over time. correctly retrieve his various items under correct in 7 out of 10 sessions (binomial test,
controlled conditions. We randomly assigned P ⬍ 0.001). Apparently, he was able to link
Department of Developmental and Comparative Psy-
the 200 items he was reportedly familiar with the novel word to the novel item based on
chology, Max-Planck Institute for Evolutionary Anthro- to 20 sets of 10 different items each. While exclusion learning, either because he knew
pology, Deutscher Platz 6, 04103 Leipzig, Germany. the owner waited with the dog in a separate that the familiar items already had names or
*To whom correspondence should be addressed. E- room, the experimenter arranged a set of because they were not novel. Four weeks
mail: fischer@eva.mpg.de items in the experimental room and then after the initial and sole exposure, we as-

1682 11 JUNE 2004 VOL 304 SCIENCE www.sciencemag.org

 REPORTS
sessed Rico’s retention of the relation be- investigation whether Rico’s accomplish- References and Notes
tween the novel word and the novel item. In ments are based on an exceptional mind or 1. P. Bloom, How Children Learn the Meanings of Words
(MIT Press, Cambridge, MA, 2000).
this retention task, we only used those objects a result of his extensive exposure to many 2. D. A. Baldwin, Dev. Psychol. 29, 832 (1993).
that Rico had successfully retrieved in the word-object combinations. Undoubtedly, 3. C. B. Mervis, J. Bertrand, Child Dev. 65, 1662 (1994).
identification task. In between the identifica- he is a highly motivated dog, and some of 4. M. Tomasello, Constructing a Language (Harvard
tion and the retention task, he had no access his talent may be accounted for by the fact Univ. Press, Cambridge, MA, 2003).
5. L. Markson, P. Bloom, Nature 385, 813 (1997).
to the target items. We placed a target item that border collies are working dogs (15).
6. S. Carey, E. Bartlett, Child Lang. Dev. 15, 29 (1978).
together with four completely novel and four More generally, dogs appear to have been 7. T. H. Heibeck, E. M. Markman, Child Dev. 58, 1021
familiar items in a room (total n ⫽ 9 items) evolutionarily selected for attending to the (1987).
and asked him first to bring a familiar item communicative intentions of humans (16– 8. O. Pfungst, Clever Hans: The Horse of Mr. von Osten
(1911), published in Classics in Psychology, 1855-
and subsequently (in the second or third trial) 18). Nevertheless, we assume that Rico’s 1914: A Collection of Key Works (Thoemmes, Bristol,
to bring the target item. Four weeks after the performance can be decomposed into a set UK, 1998).
identification task, he correctly retrieved the of simpler mechanisms. These consist of (i) 9. Further details on materials and methods and a video
target item in 3 out of 6 sessions (P ⬍ 0.1). his acquisition of the principle that objects clip demonstrating Rico’s performance during a trial
are available on Science Online.
This retrieval rate is comparable to the per- have labels; (ii) a general learning mecha- 10. C. J. Warden, L. H. Warner, Q. Rev. Biol. 3, 1 (1928).
formance of 3-year-old toddlers (1, 5). In the nism, namely learning by exclusion (emer- 11. C. A. Young, Appl. Anim. Behav. Sci. 32, 75 (1991).
other cases, he brought one of the unfamiliar gent matching) (19); and (iii) the ability to 12. H. W. L. Miles, S. E. Harper, in Hominid Culture in
items and never one of the familiar items. We store that knowledge in memory. There- Primate Perspective, D. Quiatt, J. Itani, Eds. (Univer-
sity Press of Colorado, Niwot, CO, 1994).
then replicated the experiment, first conducting fore, our results strongly support the view 13. R. J. Schusterman, K. Krieger, Psychol. Rec. 34, 3

Downloaded from www.sciencemag.org on June 28, 2007

a new set of identification tasks using novel that a seemingly complex linguistic skill (1984).
items. When he was tested for retention of the previously described only in human chil- 14. L. M. Herman, D. G. Richards, J. P. Wolz, Cognition 16,
novel word-object combinations 10 min after dren may be mediated by simpler cognitive 129 (1984).
15. R. Coppinger, R. Schneider, in The Domestic Dog: its
the identification task, he correctly retrieved the building blocks that are also present in Evolution, Behaviour and Interactions with People, J.
target item in 4 out of 6 trials (P ⬍ 0.02). another species. Whether Rico’s ability to Serpell, Ed. (Cambridge Univ. Press, Cambridge, 1995).
These experiments demonstrate that Rico form a link between a label and an object is 16. B. Hare, M. Brown, C. Williamson, M. Tomasello,
reliably associates arbitrary acoustic patterns Science 298, 1634 (2002).
homologous to children’s knowledge about
17. J. Call, J. Bräuer, J. Kaminski, M. Tomasello, J. Comp.
(human words) with specific items in his the names of things remains a matter for Psychol. 117, 257 (2003).
environment. Apparently, Rico’s extensive further investigation. Clearly, from early 18. A. Miklosi et al., Curr. Biol. 13, 763 (2003).
experience with acquiring the names of ob- on, toddlers have a much broader knowl- 19. K. M. Wilkinson, W. V. Dube, W. J. McIlvane, Psychol.
jects allowed him to establish the rule that edge than Rico about the meaning of words, Rec. 48, 407 (1998).
20. J. Fischer, Anim. Behav. 67, 655 (2004).
things can have names. Consequently, he was and they can distinguish between different 21. M. D. Hauser, N. Chomsky, W. T. Fitch, Science 298,
able to deduce the referent of a new word on functions of words such as verbs, adjec- 1569 (2002).
the basis of the principle of exclusion when tives, and proper nouns. Moreover, children 22. T. J. Bergmann, J. C. Beehner, D. L. Cheney, R. M.
presented with a novel item along with a set are able to use their newly acquired knowl- Seyfarth, Science 302, 1234 (2003).
23. We thank S. Baus and her family for allowing us to
of familiar items (13, 14). This corresponds edge productively; that is, they are able to study Rico and for her enthusiastic participation in
to the acquisition of the novel-name– say the words whose meaning they have this study. R. Mundry gave statistical advice, and C.
nameless category principle (3) and also to identified through fast mapping. Nonethe- Teufel, M. Hauser, and three anonymous reviewers
provided valuable comments on the manuscript.
the avoidance of lexical overlap described in less, our findings corroborate the assump- Funding by the Deutsche Forschungsgemeinschaft to
children (4 ). Moreover, Rico was able to tion that listeners’ ability to attach meaning J.F. (grant Fi707/4) is gratefully acknowledged.
store this knowledge about the link between to specific sounds evolved much earlier
word and object in memory, because he was than, and independently from, a flexible Supporting Online Material
www.sciencemag.org/cgi/content/full/304/5677/1682/
able to correctly retrieve the target item from production of specific sound patterns (20). DC1
a set of novel and familiar items both imme- That is, some of the perceptual and cogni- Materials and Methods
diately after introduction of the novel word- tive mechanisms that may mediate the com- Movie S1
object combination and 4 weeks later. prehension of speech were already in place
It remains a matter for further empirical before early humans began to talk (21, 22). 15 March 2004; accepted 26 April 2004

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