consideration of color alone can give a misleading impression of the three approaches to category coordination: the nativist, empiricist and culturalist models. empiricist models can benefit from a wider range of correlational information in the environment. also, all three approaches may explain a set of perceptual categories within the human repertoire. finally, a suggestion is offered for supplementing the naming game by varying the social status of agents.

“Sociosexuality from Argentina to Zimbabwe: A 48-nation study of sex, culture, and strategies of human mating” delivers on its title. By combining empiricism and careful hypothesis testing, it not only contributes to our current knowledge but also points the way to further advances.

Extending the findings of this work: Tribal peoples need study. Monogamy as marital institution and monogamy as sociosexual orientation must be separated. Sociosexuality must be considered as an aspect of somatic as well as reproductive effort; third-party interventions in sociosexuality need attention; and multiple sociosexual orientations, with frequency-dependent fitness payoffs equal at equilibrium, need to be modeled.

Men and women report having significantly different numbers of sexual partners, which is impossible in a large sample. Schmitt's target article is no exception. This focuses discussion on the nature of the samples, their heterogeneity, and the locale they are drawn from. Further, we query how humans determine, for example, sex ratio, in the context of large numbers.

to vallortigara & rogers's (v&r's) evidence of everyday directional asymmetries in the natural environment of a variety of species, we offer one more example for human beings. it is the bias for holding an infant on the left side, and it illustrates several themes in the target article.

Schmitt's study provides strong support for sexual strategies theory (Buss & Schmitt 1993) – that men and women both have evolved a complex menu of mating strategies, selectively deployed depending on personal, social, and ecological contexts. It also simultaneously refutes social structural theories founded on the core premise that women and men are sexually monomorphic in their psychology of human mating. Further progress depends on identifying evolved psychological design features sensitive to the costs and benefits of pursuing each strategy from the menu, which vary across mating milieus. These design features, like many well-documented mating adaptations, are likely to be highly sex-differentiated.

Studies with humans have failed to produce evidence that any direct causal relation exists between the asymmetry of one function in an individual and the asymmetry of a different function in that individual. Without such evidence, factors external to an individual’s nervous system, such as social interactions, may play crucial roles in explaining the directions of all asymmetries at all levels.

Schmitt finds that national sex ratios predict levels of sociosexuality, but how we should interpret this result is unclear for both methodological and conceptual reasons. We criticize aspects of Schmitt's theorizing and his analytic strategy, and suggest that some additional analyses of the data in hand might be illuminating.

an evolutionarily stable strategy (ess) may apply to characters expressed across species for predation and feeding, because these characters are conservative. however, the evolution of complex, polymorphic behaviors is more difficult to define as an ess. lateralization may be selective for certain simple traits, but lateralization of complex traits is likely the result of coadaptation of otherwise non-lateralized features.

Schmitt has equivocated about the underlying psychology of sociosexuality, but from the data presented in the target article, it would appear that he has drawn out the underlying cognitive architecture. In this commentary, I describe this architecture and discuss two emerging hypotheses about heterosexual and homosexual male sociosexuality.

i suggest that a communicative context that has the potential to establish and maintain a shared advantage of behavioral lateralization should be identified in the domain of sexual selection, specifically in the interactions that individuals exploit to assess the fitness of potential mates.

Schmitt's findings provide little evidence that sex differences in sociosexuality are explained by evolved dispositions. These sex differences are better explained by an evolutionary account that treats the psychological attributes of women and men as emergent, given the biological attributes of the sexes, especially female reproductive capacity, and the economic and social structural aspects of societies.

Previous research has suggested that offspring sex ratio may be influenced by the actions of prenatal sex steroids, principally androgens. The relative length of the second (index finger) to the fourth digit (ring finger) has been reported to be a proxy to prenatal testosterone levels. This trait is sexually dimorphic, such that males display a significantly lower 2D:4D ratio (indicating higher testosterone exposure), and this dimorphism appears robust across different populations. We suggest that digit ratio (2D:4D) may form a useful marker to help explain variation in sex ratio and sociosexuality.

the general structure of steels & belpaeme's (s&b's) central premise is appealing. theoretical stances that focus on one type of mechanism miss the fact that multiple mechanisms acting in concert can provide convergent constraints for a more robust capacity than any individual mechanism might achieve acting in isolation. however, highlighting the significance of complex constraint interactions raises the possibility that some of the relevant constraints may have been left out of s&b's own models. although abstract modeling can help clarify issues, it also runs the risk of oversimplification and misframing. a more subtle implication of the significance of interacting constraints is that it calls for a close relationship between theoretical and empirical research.

Similar to directional asymmetries in animals, language lateralization in humans follows a bimodal distribution. A majority of individuals are lateralized to the left and a minority of individuals are lateralized to the right side of the brain. However, a biological advantage for either lateralization is lacking. The scenario outlined by Vallortigara & Rogers (V&R) suggests that language lateralization in humans is not specific to language or human speciation but simply follows an evolutionarily conserved organizational principle of the brain.

sunstein argues that heuristics misguide moral judgments. principles that are normally sound falter in unusual cases. in particular, heuristics generate erroneous judgments about regulation of risks. sunstein's map of moral reasoning omits some prominent contours. the simple heuristics he suggests neglect a reasoner's attempt to balance the pros and cons of regulating a risk.

Vallortigara & Rogers (V&R) assume that the alignment of escape responses in gregarious species is the central evolutionary organizer of a wide range of cerebral asymmetries. Although it is indeed likely that the benefits of a population asymmetry in social species outweigh its costs, it is hard to see (a) why the population should not oscillate between two subgroups with mirror-image asymmetries, (b) why solitary animals should keep their inherited population asymmetry despite a resulting fitness reduction, and (c) and why so many vertebrate species have comparable cerebral asymmetries.

The target article effectively assesses multiple hypotheses for human sexuality, demonstrating support for a complex, integrated perspective. However, care must be taken when extrapolating human universal patterns from specific cultural subsets without appropriate ethnographic contexts. Although it makes a strong contribution to the investigation of human sexuality, the basal reliance on a reductionist perspective constrains the full efficacy of this research.

Schmitt recognized that research is needed to identify other factors associated with sex ratio and with sociosexuality that may explain cross-cultural variation in sexual behavior. One such factor may be the risk of sperm competition. Sperm competition theory may lead us to a more complete explanation of cultural variation in sexual behavior.

steels & belpaeme's (s&b's) simulations contain all the right components, but they are put together wrongly. color categories are unrepresentative of categories in general and language is not merely naming. language evolved because it provided a powerful new way to acquire categories (through instruction, rather than just the old way of other species, through trial-and-error experience). it did not evolve so that multiple agents looking at the same objects could let one another know which of the objects they had in mind, co-coining names for them on the fly.