Human mating strategies are contingent on individual prospects. Gangestad & Simpson provide a useful framework to explore these differing prospects, but do not take sufficient account of what is known ethnographically about mating decisions. Women often do not select their own long term mates. Men often have two or more long term mates, and can invest in the offspring of short term matings also.

Gangestad & Simpson's central premise regarding individual differences is applied to their facultative-argument based on mating- strategy, for individual differences in susceptibility to contextual effects. Some individuals may be relatively fixed strategists who are rather unresponsive to context when it comes to mating, whereas others, perhaps most, may be, as G&S propose, flexible strategists.

The emphasis on individual differences in evolutionary theories is important and has not received adequate attention. Strategic Pluralism makes a major contribution by addressing these issues, but like other evolutionary models (e.g., game theory) does not articulate the specific mechanisms underlying strategy selection. Specification of such mechanisms is an essential next step in the development of these models.

Gangestad & Simpson make a major contribution by highlighting the importance of mate choice for good genes, the costs of alternative strategies, and tradeoffs inherent in human mating. By downplaying sex differences and ignoring the nongenetic adaptive benefits of short term mating, however, they undermine their goal of “strategic pluralism” by presenting a theory devoid of many documented complexities of human mating.

The adaptive trade-offs between long- and short-term matings may be mediated or at least reflected partially by the trade-offs between the relative reinforcement obtained through a greater frequency of intercourse (typically greater among cohabitants) versus a greater frequency of partner change. The differing correlates of each approach and meshing with the Sexual Strategies Theory of Gangestad & Simpson are discussed.

Data support the claim from the target article that women, both cross-culturally and historically, have employed a variety of mating strategies, marrying but also engaging in short-term unions. But those strategies appear to be practiced simultaneously and not conditionally as Gangestad & Simpson propose, a finding consistent with assumed constraints on the potential reproductive success of females.

Therapists and their patients must deal with the negative sequelae of short term mating strategies. Implications for therapy of Gangestad & Simpson's strategic pluralism theory are compared with those of Buss's sexual strategies theory and Eagly's social role theory. Naive theories held by therapists and patients, as well as prevailing societal views, are posited as influential in determining the course and outcome of therapy.

The strategic pluralism model depends upon pathogen prevalence and environmental hardship being independent. Evidence is presented that they are positively correlated. The rise in short-term mating strategy in the United States is better explained by changes in the operational sex ratio than by increases in pathogen prevalence. Nonetheless, in highlighting the advantages of a high-investment strategy to less attractive males, Gangestad & Simpson's model helps to clarify the dynamics of frequency-dependent selection.

Gangestad & Simpson's model of the evolution of within-sex differences in reproductive strategies requires a degree of female choice that probably did not exist because of male coercion. We argue as well that the tradeoff between current and future reproduction accounts for more of the within-sex differences in reproductive strategies than the “good-genes-good parenting” tradeoff they propose.

We are not convinced by Gangestad & Simpson that differential mating strategies within each sex would be greater than such strategies between sexes. The target article does not provide actual evidence of human males who do not desire mating with multiple females, or evidence that the benefits for females of short-term matings with multiple males have ever outweighed the associated costs.

Gangestad & Simpson review sexual selection theory and discuss their work on fluctuating asymmetry and mate preference in humans. We question some aspects of their account and mention problems with the data. We also suggest that more theoretical work on complex but realistic mating systems is required.

The expansion of human evolutionary theory into the domain of personal and environmental determinants of mating strategies is applauded. Questions are raised about the relation between fluctuating asymmetry (FA), testosterone, and body size and their effects on male behavior and outcomes. Low FA males' short-term mating pattern is considered in the context of an evolved tendency for closer and longer human relationships.

Gangestad & Simpson's account of the role of good-gene sexual selection in conditional human mating strategies is reasonably convincing, but could be more so with a little more attention to (1), dropping unnecessary sub hypotheses and especially (2) the inclusion of alternative evolutionary explanations.

An alternative interpretation of Gangestad & Simpson's findings features the assumption that only a subgroup of those men who are low in fluctuating asymmetry are typically available for short-term mating. In general, these philandering men do not offer higher genetic quality than men who are securely attached to long-term mates.

Conditional mating strategies and within-sex variation in mating patterns occur across a wide range of primate taxa. Attempts to model the evolution of human mating strategies should incorporate current primatological data sets and phylogenetic perspectives. However, comparisons between interview and questionnaire-based human behavioral data and observationally and experimental generated nonhuman behavioral data should be conducted with prudence.

Genes controlling the choice of sexual strategy must be sensitive to critical environmental contingencies, including the presence of other strategically relevant genetic traits. To determine which strategy works best for each individual, one must assess both its environment and itself within that environment. Psychosexual development involves an assessment of sociosexual affordances, strategically calibrating optimal utilization of physical and psychosocial assets.

Proxies of mate value must be evolutionarily salient. Gangestad & Simpson (G&S) have made a good case that fluctuating asymmetry is an important proxy of male mate value that correlates well with genetic and developmental quality. The use of financial variables as proxies for male investment ability by Gangestad, Simpson, and virtually every other investigator of human mating in evolutionary perspective, is, however, more problematic.

Gangestad & Simpson present an evolutionary functional analysis of mating strategies. This commentary interprets their argument using a central concept from life history theory, return from investment. Incorporating return from investment allows further specification of costs and benefits from short-term mating in women as well as men and in ecological settings of high environmental variation in mortality and resource availability.

Critics of evolutionary psychology object that it is not rigorous science compared to other evolutionary science. Advocates reply that it is rigorous science, and that the critics are uninformed. Still, informed people having opposing preconceptions of what counts as rigor may reach opposing evaluative conclusions. I shall clarify the very idea of rigorous evolutionary histories in relation to the basic objection that “evolution without history” is not rigorous.

Dynamical simulations of male and female mating strategies illustrate how traits such as restrictedness constrain, and are constrained by, local ecology. Such traits cannot be defined solely by genotype or by phenotype, but are better considered as decision rules gauged to ecological inputs. Gangestad & Simpson's work draws attention to the need for additional bridges between evolutionary psychology and dynamical systems theory.