In The Secret of Our Success, Joseph Henrich claims that human beings are unique—different from all other animals—because we engage in cumulative cultural evolution. It is the technological and social products of cumulative cultural evolution, not the intrinsic rationality or ‘smartness’ of individual humans, that enable us to live in a huge range of different habitats, and to dominate most of the creatures who share those habitats with us. We are sympathetic to this general view, the latest expression of the (...) ‘California school’s’ view of cultural evolution, and impressed by the lively and interesting way that Henrich handles evidence from anthropology, economics, and many fields of biology. However, because we think it is time for cultural evolutionists to get down to details, this essay review raises questions about Henrich’s analysis of both the cognitive processes and the selection processes that contribute to cumulative cultural evolution. In the former case, we argue that cultural evolutionists need to make more extensive use of cognitive science, and to consider the evidence that mechanisms of cultural learning are products as well as processes of cultural evolution. In the latter case, we ask whether the California school is really serious about selection, or whether it is offering a merely ‘kinetic’ view of cultural evolution, and, assuming the former, outline four potential models of cultural selection that it would be helpful to distinguish more clearly. (shrink)

In order to formulate hypotheses about the evolutionary underpinnings that preceded the first glimmerings of language, mother-infant gestural and vocal interactions are compared in chimpanzees and humans and used to model those of early hominins. These data, along with paleoanthropological evidence, suggest that prelinguistic vocal substrates for protolanguage that had prosodic features similar to contemporary motherese evolved as the trend for enlarging brains in late australopithecines/early Homo progressively increased the difficulty of parturition, thus causing a selective shift toward females that (...) gave birth to relatively undeveloped neonates. It is hypothesized that hominin mothers adopted new foraging strategies that entailed maternal silencing, reassuring, and controlling of the behaviors of physically removed infants (i.e., that shared human babies' inability to cling to their mothers' bodies). As mothers increasingly used prosodic and gestural markings to encourage juveniles to behave and to follow, the meanings of certain utterances (words) became conventionalized. This hypothesis is based on the premises that hominin mothers that attended vigilantly to infants were strongly selected for, and that such mothers had genetically based potentials for consciously modifying vocalizations and gestures to control infants, both of which receive support from the literature. Key Words: bipedalism; brain size; chimpanzees; foraging; gestures; hominins; infant riding; motherese; prosody; protolanguage. (shrink)

Motor development – traditionally studied in WEIRD populations – falls victim to assumptions of universality similar to other domains described by Henrich et al. However, cross-cultural research illustrates the extraordinary diversity that is normal in motor skill acquisition. Indeed, motor development provides an important domain for evaluating cultural challenges to a general behavioral science.

The Pirahã language challenges simplistic application of Hockett’s nearly universally accepted design features of human language by showing that some of these features may be culturally constrained. In particular, Pirahã culture constrains communication to nonabstract subjects which fall within the immediate experience of interlocutors. This constraint explains a number of very surprising features of Pirahã grammar and culture: the absence of numbers of any kind or a concept of counting and of any terms for quantification, the absence of color terms, (...) the absence of embedding, the simplest pronoun inventory known, the absence of "relative tenses," the simplest kinship system yet documented, the absence of creation myths and fiction, the absence of any individual or collective memory of more than two generations past, the absence of drawing or other art and one of the simplest material cultures documented, and the fact that the Pirahã are monolingual after more than 200 years of regular contact with Brazilians and the Tupi-Guarani-speaking Kawahiv. (shrink)

A cultural change occurred roughly 40,000 years ago. For the first time, there was evidence of belief in unseen agents and an afterlife. Before this time, humans did not show widespread evidence of being able to think about objects, persons, and other agents that they had not been in close contact with. I argue that one can explain this transition by appealing to a population increase resulting in greater exoteric (inter-group) communication. The increase in exoteric communication triggered the actualization of (...) a dormant potential for greater syntactic computational power; specifically it triggered syntactic movement. Syntactic movement, in turn, made possible variable binding, which crucially figures into cognition by description, a naturalistic analogue of Russell’s knowledge by description. Cognition by description made possible the ability to conceive of things one had never experienced, such as mythological beings, places only visited by the dead, and so forth. The Amazonian Pirahã provide some corroboration for this hypothesis, since they exhibit the combination of traits here attributed to Middle Paleolithic individuals, namely exclusively esoteric (intra-group) communication, evident lack of syntactic movement, and a limitation to knowledge (cognition) by acquaintance. (shrink)

This paper aims to explore a potential connection between two hypotheses recently put forward in the context of language evolution. One hypothesis argues that some human-specific change in the hominin brain developmental program habilitated the neuronal workspace that enabled “cognitive modernity” to unfold, also resulting in our globularized braincase. The other argues that the cultural niche resulting from our self-domestication favored the emergence of natural languages. In this article we document numerous links between the genetic changes we have claimed may (...) have brought about globularization and neural crest cells, which have been claimed to explain the constellation of distinctive traits found in all domesticated mammals. If these links turn out to be as robust as we think they are, globularization and self-domestication may well be closely related phenomena in the context of human evolution. (shrink)

Why are children better language learners than adults despite being worse at a range of other cognitive tasks? Here, we explore the role of multiword sequences in explaining L1–L2 differences in learning. In particular, we propose that children and adults differ in their reliance on such multiword units in learning, and that this difference affects learning strategies and outcomes, and leads to difficulty in learning certain grammatical relations. In the first part, we review recent findings that suggest that MWUs play (...) a facilitative role in learning. We then discuss the implications of these findings for L1–L2 differences: We hypothesize that adults are both less likely to extract MWUs and less capable of benefiting from them in the process of learning. In the next section, we draw on psycholinguistic, developmental, and computational findings to support these predictions. We end with a discussion of the relation between this proposal and other accounts of L1–L2 difficulty. (shrink)