In this article, we develop a hierarchical Bayesian model of learning in a general type of artificial language‐learning experiment in which learners are exposed to a mixture of grammars representing the variation present in real learners’ input, particularly at times of language change. The modeling goal is to formalize and quantify hypothesized learning biases. The test case is an experiment (Culbertson, Smolensky, & Legendre, 2012) targeting the learning of word‐order patterns in the nominal domain. The model identifies internal biases of (...) the experimental participants, providing evidence that learners impose (possibly arbitrary) properties on the grammars they learn, potentially resulting in the cross‐linguistic regularities known as typological universals. Learners exposed to mixtures of artificial grammars tended to shift those mixtures in certain ways rather than others; the model reveals how learners’ inferences are systematically affected by specific prior biases. These biases are in line with a typological generalization—Greenberg's Universal 18—which bans a particular word‐order pattern relating nouns, adjectives, and numerals. (shrink)

One view of language is that it emerged in a single step in Homo sapiens, and depended on a radical transformation of human thought, involving symbolic representations and computational rules for combining them. I argue instead that language should be viewed as a communication system for the sharing of thoughts, and that thought processes themselves evolved well before the capacity to share them. One property often considered unique to language is generativity—the capacity to generate a potentially infinite variety of sentences. (...) I suggest that generativity is derived from the understanding of space and the capacity to recall or construct spatiotemporal scenarios, and probably goes far back in the evolution of animals that move in spatial habitats. Another property essential to language is theory of mind, the ability to understand what others are thinking, which probably emerged from animal empathy and became more complex in hominin evolution. Language evolved for the sharing of experiences, whether remembered or constructed, perhaps initially through pantomime but gradually conventionalized into standardized forms, including speech. These developments probably took place gradually during the Pleistocene, rather than as a sudden event in the evolution of H. sapiens. (shrink)

Euan Macphail’s work and ideas captured a pivotal time in the late 20th century when behavioral laws were considered to apply equally across vertebrates, implying equal intelligence, but it was also a time when behaviorism was challenged by the view that language was unique to humans, and bestowed a superior mental status. Subsequent work suggests greater continuity between humans and their forebears, challenging the Chomskyan assumption that language evolved in a single step {“the great leap forward”) in humans. Language is (...) now understood to be based on an amalgam of cognitive functions, including mental time travel, theory of mind, and what may be more broadly defined as imagination. These functions probably evolved gradually in hominin evolution and are present in varying degrees in nonhuman species. The blending of language into cognition provides both for interspecies differences in mental function, and continuity between humans and other species. What does seem to be special to humans is the ability to communicate the contents of imagination, although even this is not absolute, and is perhaps less adaptive than we like to think. (shrink)

Two computer simulations are investigated that model interaction of cultural evolution of language and biological evolution of adaptations to language. Both are agent-based models in which a population of agents imitates each other using realistic vowels. The agents evolve under selective pressure for good imitation. In one model, the evolution of the vocal tract is modeled; in the other, a cognitive mechanism for perceiving speech accurately is modeled. In both cases, biological adaptations to using and learning speech evolve, even though (...) the system of speech sounds itself changes at a more rapid time scale than biological evolution. However, the fact that the available acoustic space is used maximally is constant, and therefore biological evolution does have a stable target. This work shows that when cultural and biological traits are continuous, their co-evolution may lead to cognitive adaptations that are strong enough to detect empirically. (shrink)

My dissertation establishes the basis for a systematic outlook on the role language plays in human cognition. It is an investigation based on a cognitive conception of language, as opposed to communicative conceptions, viz. those that suppose that language plays no role in cognition. I focus, in Chapter 2, on three paradigmatic theories adopting this perspective, each offering different views on how language contributes to or changes cognition. -/- In Chapter 3, I criticize current views held by dual-process theorists, and (...) I develop a picture of the complex interaction between language and cognition that I deem more plausible by using resources from the literature on the evolution of the faculty of language. Rather than trying to find one general explanation for all cognitive processes, I take seriously the idea that our mind is composed of many subsystems, and that language can interact and modify each in different ways. There is no reason offered in the empirical literature—besides maybe parsimony—that suggest that language has to interact in the same ways with all cognitive processes. Yet, this is seemingly taken for granted, especially within dual-process approaches. -/- On my view, it is a central requirement for a theory of the role of language in cognition to explain how language might have effects, at once, on and within various parts of cognition. In Chapter 4, I explore how this framework can modify how we think about some experiments in psychology, specifically in research on categorization. My idea is that language, once it evolved, changed how some cognitive capacities worked and interacted with each other, but did so in more than one or two ways. Cognitive systems are changed in very different ways—sometimes the transformation is very subtle, such as our way of forming categories by using how similar objects are, while other times it is deep and changes the very way the system works. (shrink)