Online research in philosophy

In 2002, Evolution and Human Behavior published a study purporting to show that the differences in toy preferences commonly attributed to girls and boys can also be found in male and female vervet monkeys, tracing the origin of these differing preferences back to a common ancestor. Despite some flaws in its design and the prima facie implausibility of some of its central claims, this research received considerable attention in both scientific circles and the popular media. In what follows, I survey some of the problems with this study that seem to be characteristic of research into sex differences in a particular research program in evolutionary psychology. I suggest that an epistemology of ignorance is at work that suppresses the methods and insights of an earlier research program, which emphasized the complexity and contingency that ultimately grounds the variety of human behaviors, in favor of one that has been widely criticized as empirically flawed and politically pernicious. I conclude with some speculative remarks on the persistence of this problematic research program in evolutionary psychology.

The defining insight of evolutionary psychology consists of bringing considerations drawn from evolutionary biology to bear on the study of human psychology. So characterized, evolutionary psychology encompasses a large range of views about the nature and evolution of human psychology as well as diverging opinions about the proper method for studying them.¹ In this article, I propose to clarify and evaluate various aspects of evolutionary psychologists’ methodology, with a special focus on their heuristics of discovery—i.e., their methods for developing plausible hypotheses—and their strategies of confirmation—i.e., their methods for providing empirical support for these hypotheses.² I will also evaluate several well-known objections raised against evolutionary psychology. Note that because views about psychology and evolution differ among evolutionary psychologists, I do not pretend to cover every method used in evolutionary psychology.³.

Scholars suggest that evolutionary psychology may provide a foundation for assumptions regarding human values. I explore this suggestion by developing two arguments regarding the permissiveness of norms regulating male and female sexual activity. The first relies on the standard rational choice assumption that people value resources, and the second relies on an assumption suggested by evolutionary psychology that actors value seeing their children successfully reach adulthood. These two assumptions produce contrasting predictions regarding sex norms. I describe the implications of these predictions for explaining cross-cultural variation and present evidence that supports the evolutionary psychology-based predictions in this context. I also suggest implications of the two approaches for explaining norms cross-nationally and within the United States. The article provides support for the utility of evolutionary psychology in developing assumptions about values.

According to the ‘mating intelligence’ theory by evolutionary psychologist Geoffrey Miller, human morality is a system of sexually selected traits which serve as costly signals to the other sex about one’s fitness and readiness to take care for possible offspring. Starting from the standard prediction of evolutionary psychology that sexual selection produces psychological sex differences in human mating strategies, ‘mating intelligence’ theory is analyzed for its compatibility with several psychological theories about sex differences in moral traits like moral reasoning, judgment and orientation. It is argued that the ‘mating intelligence’ theory, as a theory about the the evolution of morality, comes too dangerously close to being unfalsifiable because it embodies some auxiliary hypotheses and vague definitions which make it practically immune to every possible empirical finding concerning sex differences in human moral traits.

In Sex, Gender and Science , Myra Hird outlines the social study of science and nature, specifically in relation to sex, sex differences, and sexuality. She examines how Western understandings of sex are based less upon understanding material sex differences than on a discourse that emphasizes sex dichotomy over sex diversity and argues for a feminist engagement with scientific debate that embraces the diversity and complexity of nature.

The Sociosexual Orientation Inventory (SOI; Simpson & Gangestad 1991) is a self-report measure of individual differences in human mating strategies. Low SOI scores signify that a person is sociosexually restricted, or follows a more monogamous mating strategy. High SOI scores indicate that an individual is unrestricted, or has a more promiscuous mating strategy. As part of the International Sexuality Description Project (ISDP), the SOI was translated from English into 25 additional languages and administered to a total sample of 14,059 people across 48 nations. Responses to the SOI were used to address four main issues. First, the psychometric properties of the SOI were examined in cross-cultural perspective. The SOI possessed adequate reliability and validity both within and across a diverse range of modern cultures. Second, theories concerning the systematic distribution of sociosexuality across cultures were evaluated. Both operational sex ratios and reproductively demanding environments related in evolutionary-predicted ways to national levels of sociosexuality. Third, sex differences in sociosexuality were generally large and demonstrated cross-cultural universality across the 48 nations of the ISDP, confirming several evolutionary theories of human mating. Fourth, sex differences in sociosexuality were significantly larger when reproductive environments were demanding but were reduced to more moderate levels in cultures with more political and economic gender equality. Implications for evolutionary and social role theories of human sexuality are discussed. Key Words: culture; gender; mating; reproduction; sex differences; sex roles; sexual strategies; sociosexuality.

The development of evolutionary approaches to psychology from Classical Ethology through Sociobiology to Evolutionary Psychology is outlined and the main tenets of today's Evolutionary Psychology briefly examined: the heuristic value of evolutionary thinking for psychology, the massive modularity thesis and the monomorphic mind thesis.

Four issues relevant to sex differences in human aggression and violence are considered. (1) The motivation for play and serious aggression in children and juvenile animals is different. Consequently, the evolutionary explanations for each may be different. (2) Sex differences in intrasexual aggression may be due to effects of the attacker or the target. There is evidence that both males and females are more physically aggressive against males and less physically aggressive against females. The evolutionary explanation for each component of the sex difference in intrasexual aggression may be different. (3) Aggression and violence are defined. The former is the attack, and the latter is the consequent injury or death. The evolutionary explanation for each may not be the same. (4) Most men and women are neither physically aggressive nor criminally violent. The evolutionary explanations of sex differences in aggression and violence should take this polymorphism into account.

The Sociosexual Orientation Inventory (SOI) was not designed to illuminate the sexually dimorphic mental mechanisms posited by evolutionary theories. Its results are therefore open to competing interpretations. Measures designed to tap the thought processes surrounding sexual experience generate findings that are more compatible with evolutionary than with social structural theory.

Analyses of between-sex differences have provided a powerful starting point for evolutionarily informed work on human sexuality. This early work set the stage for an evolutionary analysis of within-sex differences in human sexuality. A comprehensive theory of human sexual strategies must address both between-sex differences and within-sex differences in evolved psychology and manifest behavior.