Which humans behave adaptively, and why does it matter?

Abstract

There has long been debate about the relevance of evolutionary theory to the study of humans. To many of us, however, the debate has shifted from whether to proceed with an evolutionary approach to how to proceed. Increasingly, it has been argued that studies of the current reproductive function of human traits make little or no contribution to the understanding of the psyche (e.g., Symons 1989). Here, on the basis of arguments about the relationship between an adaptation and an adaptive outcome, and a review of studies that assess current adaptiveness, I argue to the contrary that knowledge of the contexts in which people do or do not behave adaptively provides important information about the nature of the mechanisms that comprise the human psyche. In particular, studies that indicate that people behave adaptively in at least some contemporary environments cast doubt on many nonevolutionary constructions of human nature, and can be used now to distinguish alternative evolutionary constructions that are at odds over many issues pentaining to the human psyche's ontogeny and evolutionary background, especially the extent to which the human psyche is general purpose.

Wealth, fertility and adaptive behaviour in industrial populations

“…In the process of measuring fertility decisions in a wide range of industrial (and pre-industrial) populations, we undoubtedly learn much about human decision-making processes (see also [11,20,74]), as well as potentially being able to identify putative evolved psychological predispositions; we believe such an approach is preferable to speculative hypotheses about our ancestral past and the a priori assumption of an evolutionary mismatch.…”

“…Whether such differences are truly 'innumerable' is, of course, an open question, and it may very well be that many evolutionarily relevant aspects of human behaviour have remained fairly constant (e.g. gathering sufficient resources, finding a suitable partner, raising a child to become competitive in the mating market; see also [20,110]). Moreover, although it is certainly plausible to suggest that we possess evolved psychological mechanisms that are not well equipped to cope with industrial environments, theories highlighting the drastically changed modern environment without specifying precisely what has changed and why, are of little explanatory value (a point also made by both Vining [2] and Pérusse [3]; see also [15]).…”

“…In addition, it was suggested that humans may be psychologically predisposed to attune decisions to those occurring in their 'reference groups' ( [20]; e.g. those of similar occupational status or education; see also [21,22] for perspectives from economics).…”

Sex differences in the events that elicit jealousy among homosexuals

“…According to Bailey et al (1994) the decrease in sexual jealousy among homosexual men may be caused by a generalized psychological mechanism (cf. Tooby & Cosmides, 1990; Turke, 1990) that inhibits individuals in investing their resources in children or adults that are nongenetically related. As a consequence, heterosexual men should see their resources put at risk by a partner's infidelity, whereas homosexual men should not, resulting in less distress in response to a partner's sexual infidelity.…”

Environments, Adaptation, and Evolutionary Medicine Should We Be Eating a Stone Age Diet?

“…Those engaged in evolutionary medicine should recognise that just as the modern world is complex, the world in which humans evolved was also heterogeneous and not confined to the Pleistocene. The ideas that I synthesise in this chapter are not new; evolutionary biologists, ecologists, palaeontologists and anthropologists have been using concepts of variability and variation to critique notions of the EEA and 'Stone Age' adaptations for the best part of two decades [13][14][15][16][17][18][19][20][21]. However, prominent advocates of Darwinian medicine repeatedly fall back on explanations for some chronic diseases that rely on a homogeneous reconstruction of 'Stone Age' environments [4,5], despite acknowledging the probability of greater complexity [1][2][3]22].…”