Cognitive specialization

If social behavior is to be considered a cognitive specialization unique to human neural architecture, it should be present in every human society.[11] To provide cross-cultural evidence that cognitive adaptations specifically support social communication, Sugiyama, Tooby, and Cosmides investigated social reasoning in a tribe in the Ecuadorian Amazon.[11] The Shiwiar, who are a hunter-horticulturalist group previously unexposed to the presented psychological stimuli, were "as highly proficient" in determining who cheated in a given situation as their counterparts in the United States.[11] This performance indicates that social communication, at least in the domain of cheater detection, is not determined by one's culture. According to Sugiyama, Tooby, and Cosimdes, the social "algorithms" discussed above are present in both Western and non-Western populations, providing strong evidence for the universality of such a skill.[8][11]

Theory of mind appears to be lacking in children with autism spectrum disorders, and this deficit is thought to be a major contributor to frequent impairments in some areas of social understanding in people with autism.[17] The fact that a developmental delay in (or absence of) theory of mind can impair social functioning—a skill imperative in the survival of the human species—is argued to be evidence for theory of mind as an adaptive cognitive specialization.[17] Understanding that others may be thinking different thoughts than I am (colloquially, "putting oneself in another person's shoes") allows humans to communicate effectively and to live in large social groups. This adaptability is what makes theory of mind a cognitive specialization, rather than just another byproduct of human evolution: humankind has unique and beneficial communication skills, and this is partially due to our ability to recognize that other people may not think or know the same things we do.[1]

Arbib puts forth a hypothesis that mirror neurons in the primate brain were a precursor to language abilities in humans.[20] Without these neurons in Broca's area in humans (which is analogous to F5 in monkeys), Arbib claims, we could not have evolved a specialization for language—which is used to explain why non-human animals do not have linguistic capabilities.[20] In addition, Meguerditchian and Vauclair have argued that our evolutionary ancestors' communicative gestures (such as threat gestures and "food begs" among baboons) established a foundation on which to build human language skills.[21] This behavior was selected for, built upon, and modified, leading to the capabilities humans have today. Early theories explained early language as an adaptive way to communicate during a hunt, but recent research has focused on ecological theories that incorporate social demands; or, as Flinn et al. put it, a "social arms race" against non-human primates.[22] As a behavior selected for over the long term, with many successful "intermediary stages," human language differs from all other social behaviors among chimpanzees, which are thought to be more gradual in their evolutionary development.[22] Further evidence for language as a cognitive specialization includes Ferreira et al.'s finding that some parts of language (for instance, syntax) can be spared in amnesia, while other abilities (like memory retention) are drastically reduced.[23] This and similar dissociations support the theory that specific neural architecture, which has evolved over time, supports language function.[23]

Linguist Noam Chomsky proposed a biological component of language, which he termed Universal Grammar.[24] According to Chomsky, an essential part of language processing is hard-wired into the human brain. This allows language to be produced with or without specific linguistic instruction (which is closely associated with the poverty of the stimulus argument).[24] All humans—and only humans—have this biological trait, but building blocks of universal grammar have been reported in other species.[25] Jackendoff argues that Universal Grammar is itself a "pre-existing cognitive specialization":[26] rather than needing explicit instruction on how to speak their native language, or having vocabulary and syntactical rules of a specific language present in their brains from birth, children seem to be genetically pre-disposed to learn language.[26] Complementary to the connection made between area F5 in macaques' brains,[20] the theory of Universal Grammar allows for an evolutionary perspective on language use as a cognitive specialization. There is some controversy, however, on whether or not Universal Grammar can have evolved by standard Darwinian evolutionary principles, or must be explained using different mechanisms.[27]

According to Nowak and Sigmund, language is essential to human life as we know it.[28] Without the ability to verbally communicate with members of our social group, there would be no reciprocity (that is, returning of favors), and no way to cooperate with one another for a greater good.[28] Some have argued that unique aspects of human language have evolved for unexpectedly beneficial reasons, besides simply asking for help or sharing information about the world. Gossip, viewed by many [29] to be a superfluous aspect of human communication, may even serve an adaptive purpose. The spread of information about other people, even if it is malicious, may serve as an indicator of social intelligence and a way to deter illicit behaviors.[29] Though gossip likely helps some humans and hinders others' social standing, it appears to be an overall benefit of the ability to produce verbal language.[29] Without an overall specialization for language (including such sub-specializations as gossip), linguists argue, humans would not be able to share information efficiently and effectively.[28]

Humankind's closest ancestors, the great apes, have evolved a number of specialized behaviors: orangutans are specialists at climbing trees, while chimpanzees and gorillas have evolved to walk on their knuckles.[1] However, in considering non-behavioral specializations, Penn et al. (2008) argue that the "profound continuity" Charles Darwin noted between human and non-human animals in the biological domain is matched by a "profound discontinuity" between human and non-human animal minds.[34] In contrast, in addition to cognitive-behavioral adaptations, it is possible that chimpanzees have acquired more socially advanced skills through natural selection, including self-recognition (indicated by chimpanzees' established ability to pass the "mirror test").[35] This task—in which a successful trial is simply one in which an animal recognizes itself in a mirror—is thought to be a basic building block of theory of mind development.[36] Rhesus monkeys have also been shown to realize when they remember certain events and items, which is considered to be an instrumental building block in the formation of social relationships, as one must remember who owes him favors, who he can trust, and who he should avoid in order to prosper in the community.[37]

More recent evidence has shown that cognitive specialization is not just present in primates: domesticated dogs may show signs of understanding human behavior and communication, indicating a social-cognitive specialization that is argued to make them more likely to receive food, shelter and love from their human owners. Being receptive to human behavioral indicators and responding accordingly has allowed dogs to survive and thrive as a species.[38] Bottlenose dolphins and elephants have also been shown to pass the "mirror test" explained above. This indication of some elementary self-awareness provides more evidence for foundational theory of mind skills in organisms throughout the animal kingdom.[39][40] Ants, bees, and other insects have also evolved behaviors consistent with various specializations, including advanced navigational skills and several basic social communication abilities.[41] Adaptive cognitive evolution has been examined in pigeons' ability to group objects (which is argued to support their processing of and adaptation to novel environments),[42] problem solving and "creative" tool modification among rooks,[43] and tool use in crows.[44]