1.REVIEW:NEUROSCIENCETheFacultyofLanguage:WhatIsIt,WhoHasIt,andHowDidItEvolve?

We conclude by making three points.

First, a practical matter: Linguists and biologists, along with researchers in the relevant branches of
psychology and anthropology, can move beyond unproductive theoretical debate to a more
collaborative, empirically focused, and comparative research program aimed at uncovering both
shared (homologous or analogous) and unique components of the faculty of language.

Second, although we have argued that most—if not all—of FLB is shared with other species, whereas
FLN may be unique to humans, this represents a tentative, testable hypothesis in need of further
empirical investigation.

Finally, we believe that a comparative approach is most likely to lead to new insights about both
shared and derived features, thereby generating new hypotheses concerning the evolutionary forces
that led to the design of the faculty of language. Specifically, although we have said relatively little
about the role of natural selection in shaping the design features of FLN, we suggest that by
considering the possibility that FLN evolved for reasons other than language, the comparative door
has been opened in a new and (we think) exciting way.
Comparative work has generally focused on animal communication or the capacity to acquire a
human-created language. If, however, one entertains the hypothesis that recursion evolved to solve
other computational problems—such as navigation, number quantification, or social relationships—
then it is possible that other animals have such abilities, but our research efforts have been targeted
at an overly narrow search space (Fig. 3).

If we find evidence for recursion in animals, but in a noncommunicative domain, then we are more
likely to pinpoint the mechanisms underlying this ability and the selective pressures that led to it.
This discovery, in turn, would open the door to another suite of puzzles: Why did humans, but no
other animal, take the power of recursion to create an open-ended and limitless system of
communication? Why does our system of recursion operate over a broader range of elements or
inputs (e.g., numbers, words) than other animals?

One possibility, consistent with current thinking in the cognitive sciences, is that recursion in animals
represents a modular system designed for a particular function (e.g., navigation) and is impenetrable
with respect to other systems. During evolution, the modular and highly domain-specific system of
recursion may have become penetrable and domain-general. This opened the way for humans—
perhaps uniquely—to apply the power of recursion to other problems. This change from domain-
specific to domain-general may have been guided by particular selective pressures, unique to our
evolutionary past, or as a consequence (by-product) of other kinds of neural reorganization. Either
way, these are testable hypotheses that highlight the importance of comparative approaches to the
faculty of language.

2The Evolution of the Language Faculty: Clarifications andImplications(Harvard)

Our current understanding of language evolution remains incomplete due to a lack of definitive
empirical data. However, we argue that progress depends on a multidisciplinary, comparative
approach that distinguishes between the shared components (FLB) and the uniquely human, possibly
minimal, components (FLN) of the language faculty. While many aspects of language—such as the
sensory-motor mechanisms and even some computational abilities—may be shared with other
species, key features like recursion and certain syntactic processes might be uniquely human.
Ultimately, all plausible hypotheses should be rigorously tested without prejudice, integrating
insights from linguistics, biology, cognitive science, and neuroscience, to reveal both the adaptive
and non-adaptive elements of language evolution.

3. Cultural Constraints on Grammar and Cognition in Pirahã Another Look at the Design Features of
Human Language by Daniel L. Everett

Short Summary Including All Key Points:

 Cultural Identity and Language Loss:

The Piraha people demonstrate that losing a language means losing a unique cultural
identity. They proudly assert, “We are not Brazilians. We are Piraha,” showing that without
their language, their identity would vanish.

 Endangerment Factors:
Their language is endangered due to external pressures—settler encroachment, Western
diseases, alcohol, and rapid cultural change—which threaten both their people and their way
of life.

 Cultural Influence on Grammar:

Everett argues that the unique grammatical features (or “gaps”) in Piraha—such as the lack
of concepts for counting, complex quantification, color terms, and perfect tense—are not
signs of cognitive deficiency but rather the result of cultural values shaping language. This
challenges the idea of an autonomous, biologically determined universal grammar.
 Broader Implications for Linguistic Theory:
These observations suggest that core aspects of language structure, including recursion and
syntactic complexity, may be influenced by culture. The differences between languages of
culturally simple and complex societies indicate that linguistic features are not immune to
sociocultural factors.
 Call for Urgent Research:
The text emphasizes the urgent need to document endangered languages like Piraha. It also
calls for more field research to explore how cultural constraints affect linguistic and cognitive
abilities, which could advance our understanding of language evolution and challenge long-
held linguistic dogmas.

 Future Directions:
Everett’s work is seen as a catalyst for new research that integrates evolutionary
perspectives, cultural influences, and linguistic theory, ultimately leading to a richer, more
nuanced understanding of human language and cognition.

4. Brain & Language

Current research shows that Broca’s area, essential for language, is also involved in recognizing
actions and coordinating manual tasks in both humans and primates. This overlap suggests that
language and manual praxis may have co-evolved, sharing a common neural network. Studies on
stone tool manufacture further support a syntax-based origin for language, highlighting neural
parallels between tool use and linguistic processing—even though some differences, such as greater
right-hemisphere involvement in tool making, remain. Overall, these findings indicate that the
evolution of language is closely tied to our ancestors' manual and technological abilities, though
more research is needed to fully understand these relationships.

o3-mini

5. Mirror neurons and the evolution of language

freed the hands from involvement in other activities, such as carry-ing things, or manufacturing tools
or other artifacts. I have sug-gested elsewhere (Corballis, 2004b) that this may explain whathas been
termed the ‘‘human revolution” (Mellars & Stringer,1989), apparently restricted to our own species,
comprising sud-den and rapid advances in technology, culture, art, bodily orna-mentation, and the
like (Mellars, 2004). But these advances haveundoubtedly influenced language itself, vastly
increasing the sheernumber and complexity of the objects and concepts that populateour lives,
which in turn may have increased the pressure to stream-line and conventionalize our words and
concepts, and to add com-plexity to sentence structure. It has also led to new forms oflanguage—the
languages of mathematics and computers. Thesefactors, rather than the switch per se, may have
altered the shapeof language. In this sense, then, what linguists have generallyunderstood as
‘‘language” may be the product of a revolution thatmay have been brought about through the
emergence of autono-mous speech, although signed languages can be easily and effec-tively
improvised to substitute for it.But asTomasello (2003b)has pointed out, linguists’ concep-tions of
language have been dominated by the languages of lit-erate, Western populations. Across the world,
languages mayvary as much as the material cultures themselves do. In nonWest-ern societies, with
relatively few material artefacts, language maytake a rather different shape, as exemplified by the
Pirahã, but isnonetheless finely tuned to the needs and customs of the culture.It is nonetheless
language, characterized by generativity and free-dom of expression. Prior to the emergence of
autonomous speech,a largely gestural form of language would presumably haveserved almost as
well, but for the psychological (rather than lin-guistic) disadvantages of the visual modality relative to
the audi-tory one.So what of mirror neurons? It is clear that the discovery of mir-ror neurons
provided strong support for the theory that languageevolved from manual gesture rather than from
primate calls. Themirror system in primates seems to provide a natural platformfor the subsequent
evolution of an intentional communicative sys-tem in which inputs are readily mapped onto outputs.
In particular,one might readily speculate as to how a gestural language, perhapseventually
resembling modern signed languages, might haveemerged from the basic properties of the primate
mirror system.The finding that intransitive actions join transitive actions in thehuman mirror system
paved the way to the use of the mirror sys-tem in communicative acts. The emergence of spoken
language re-quires the further insight that speech itself can be regarded as agestural system, but
additional steps are required to account forthe incorporation of vocalization into the mirror system,
alongwith anatomical changes to provide the necessary flexibility of vo-cal signaling.Of course, there
must be more to language than can be under-stood in terms of mirror neurons themselves, or even
of the ex-tended mirror system. Even so, it is remarkable how closely thelanguage areas of the
human brain map on to the extended mirrorsystem as identified in the primate brain (cf.Iacoboni &
Wilson,2006). This raises the question of whether the components of themirror system have simply
grown more complex to accommodatethe added complexities of language, or whether brain areas
unre-lated to the mirror system are involved. Is language at root a mat-ter of grasping? Thus the
anterior component of the mirror systemmay have differentiated and elaborated to enable syntax,
the pos-terior components to apprehend context and more subtle inten-tion. Associative principles
must also be incorporated. The mirrorneurons in the monkey that fire to the sounds of actions such
astearing paper and those in humans that fire to words describingmovements, where there is no
somatotopic mapping, clearly implycomplex learning.Finally, language could not have evolved in a
vacuum. I sug-gested that one capacity, possibly unique to humans, that mayhave driven the
evolution of language was mental time travel—the ability to reconstruct past events and imagine
future ones,and even to construct entirely fictional ones. Language may haveevolved to allow our
mental wanderings to be shared, to the ben-efit of the group as well as of the individual. The
generativity oflanguage and the emergence of linguistic devices to signal timeand space seem
precisely tuned to the requirements of communi-cating events, real or imaginary. This is not to say
that mental timetravel preceded language in evolution. My guess is that they co-evolved, to
comprise the distinctive structure of the human mind

6. Computational and evolutionary aspectsof language

Humans and chimpanzees share a common ancestor, having diverged from each other around 5
million years ago, making chimpanzees our closest living relatives in the evolutionary tree. Despite
this close genetic relationship, there are profound differences in their cognitive abilities and
communication systems. Chimpanzees possess a complex system of conceptual understanding and
engage in rich social interactions, demonstrating behaviors such as tool use, problem-solving, and
emotional expression. However, their communication system is limited to gestures, facial
expressions, and vocalizations, which lack the structural complexity of human language. In contrast,
humans have evolved advanced cognitive abilities that support the development of language,
characterized by features such as syntax, grammar, and arbitrary symbols that allow for the
expression of abstract ideas. This evolution of language in humans is believed to be the result of
genetic modifications that altered brain structures, particularly areas responsible for linguistic
processing like Broca’s and Wernicke’s areas. The development of language likely occurred through
incremental evolutionary steps, influenced by natural selection, where pre-existing cognitive skills
were repurposed for new linguistic functions. A key feature distinguishing humans from chimpanzees
is the presence of Universal Grammar (UG)—an innate biological framework that enables humans to
acquire language naturally and efficiently, regardless of the specific language environment. While
chimpanzees exhibit cultural behaviors and can learn simple sign language or symbol-based
communication in captivity, they do not possess UG or the capacity for language evolution through
biological means. In humans, both biological evolution (reflected in genetic changes) and cultural
evolution (through the transmission of language across generations) have played critical roles in
shaping our unique linguistic abilities. Understanding these differences helps us explore not just how
language evolved, but also how genetic and cognitive developments contributed to the distinct
trajectories of humans and chimpanzees.