One of our main goals with “Expression unleashed” was to highlight the distinctive, ostensive nature of human communication, and the many roles that ostension can play in human behavior and society. The commentaries we received forced us to be more precise about several aspects of this thesis. At the same time, no commentary challenged the central idea that the manifest diversity of human expression is underpinned by a common cognitive unity. Our reply is organized around six issues: (1) languages and their cultural evolution; (2) the pervasiveness of expression in human behavior; (3) artificial intelligence and ostensive communication; (4) communication in other animals; (5) the ecology and evolution of ostensive communication; and (6) biolinguistics and pragmatics.

We argue that people choosing prosocial distribution of goods (e.g., in dictator games) make this choice because they do not want to disappoint their partner rather than because of a direct preference for the chosen prosocial distribution. The chosen distribution is a means to fulfil one’s partner’s expectations. We review the economic experiments that corroborate this hypothesis and the experiments that deny that beliefs about others’ expectations motivate prosocial choice. We then formulate hypotheses about what types of expectation motivate someone to do what is expected: these are justifiable hopeful expectations that are clearly about his own choices. We experimentally investigate how people modulate their prosociality when they face low or unreasonably high expectations. In a version of a dictator game, we provide dictators with the opportunity to modulate their transfer as a function of their partner’s expectations. We observe that a significant portion of the population is willing to fulfil their partner’s expectation provided that this expectation expresses a reasonable hope. We conclude that people are averse to disappointing and we discuss what models of social preferences can account for the role of expectations in determining prosocial choice, with a special attention to models of guilt aversion and social esteem.

We argue for a relevance-guided learning mechanism to account for both innovative reproduction and faithful imitation by focusing on the role of communication in knowledge transmission. Unlike bifocal stance theory, this mechanism does not require a strict divide between instrumental and ritual-like actions, and the goals they respectively fulfill (material vs. social/affiliative), to account for flexibility in action interpretation and reproduction.

Human expression is open-ended, versatile, and diverse, ranging from ordinary language use to painting, from exaggerated displays of affection to micro-movements that aid coordination. Here we present and defend the claim that this expressive diversity is united by an interrelated suite of cognitive capacities, the evolved functions of which are the expression and recognition of informative intentions. We describe how evolutionary dynamics normally leash communication to narrow domains of statistical mutual benefit, and how expression is unleashed in humans. The relevant cognitive capacities are cognitive adaptations to living in a partner choice social ecology; and they are, correspondingly, part of the ordinarily developing human cognitive phenotype, emerging early and reliably in ontogeny. In other words, we identify distinctive features of our species' social ecology to explain how and why humans, and only humans, evolved the cognitive capacities that, in turn, lead to massive diversity and open-endedness in means and modes of expression. Language use is but one of these modes of expression, albeit one of manifestly high importance. We make cross-species comparisons, describe how the relevant cognitive capacities can evolve in a gradual manner, and survey how unleashed expression facilitates not only language use, but also novel behaviour in many other domains too, focusing on the examples of joint action, teaching, punishment, and art, all of which are ubiquitous in human societies but relatively rare in other species. Much of this diversity derives from graded aspects of human expression, which can be used to satisfy informative intentions in creative and new ways. We aim to help reorient cognitive pragmatics, as a phenomenon that is not a supplement to linguistic communication and on the periphery of language science, but rather the foundation of the many of the most distinctive features of human behaviour, society, and culture.

Are communicators perceived as committed to what they actually say (what is explicit), or to what they mean (including what is implicit)? Some research claims that explicit communication leads to a higher attribution of commitment and more accountability than implicit communication. Here we present theoretical arguments and experimental data to the contrary. We present three studies exploring whether the saying–meaning distinction affects commitment attribution in promises, and, crucially, whether commitment attribution is further modulated by the degree to which the hearer will actually rely on the promise. Our results support the conclusion that people perceive communicators to be committed to ‘what is meant’, and not simply to ‘what is said’. Our findings add to the experimental literature showing that the saying–meaning distinction is not as pivotal to social relations as often assumed, and that its role in commitment attribution might be overestimated. The attribution of commitment is strongly dependent on the (mutually known) relevance of ‘what is meant’.