Abstract
The target meta-analysis (Wood, Kressel, Joshi, & Louie, 2014) raises a number of red flags for research on menstrual shifts in women’s psychology. In this commentary, I particularly address one: the near-absent attention to sociocultural forces in this body of work. I use social neuroendocrinology as one example of a research paradigm that integrates both evolution and socialization into studies of human behavior. I argue that incorporating attention to social constructions actually provides clearer answers to evolutionary questions and also fills the biobehavioral comparative mandate by seriously attending to human specificities alongside cross-species generalities. I close by noting that human bodies simultaneously reflect evolved and sociocultural forces, an understanding that undergirds contemporary biobehavioral research.
Wood et al. (2014) present a careful and thorough meta-analysis of research on menstrual shifts in women’s mating preferences. This is useful and timely given the excitement this field has generated. Seeing all the details together leads to some head-scratching observations, though. How can researchers use at least nine different fertility windows? How can these windows differ by fully 13 days? Why don’t the same researchers use the same windows across studies? And, how can such broad windows be justified in the face of empirical precedent for more narrow constraints?
The critique from Wood et al. (2014) that I particularly want to address here is that culture tends to be overlooked in this body of work, resulting in only partial understandings of human evolution. There are biosocial alternatives to evolutionary psychology, detailed in the article (eg., Eagly & Wood, 2013). I want to offer another: social neuroendocrinology is a way to study evolved neurobiological substrates for social behavior while attending to sociocultural factors (van Anders & Watson, 2006). It asks hormonal questions that have both evolution and socialization in their answers. It is comparative as behavioral biology generally is: social neuroendocrinology can be used to study evolved human behavior with interchanging lenses of human specificities and cross-species generalities.
Comparative approaches are useful and widespread in biobehavioral research. Rightly so, because insights from some species can be useful for others. For example, Wood et al. (2014) critique the overfocus on the immunocompetence handicap hypothesis (ICHH) in the menstrual shift work. Comparative insights support this critique, because evidence from most species is nonsupportive and the ICHH is largely seen as unfalsifiable. Menstrual shift researchers thus have a special burden of demonstrating its human-specific applicability both empirically and theoretically before using it as a foundation for other hypotheses.
There are special cases of human specificities to study in evolutionary research, including the sociocultural forces for which Wood et al. (2014) call for more attention. Evolutionary research that does not attend to social constructions tends to uncritically reflect them back. Sidelining culture in the study of evolution is outdated, as noted by Wood et al., but how to meaningfully incorporate both? The steroid/peptide theory of social bonds (S/P theory; van Anders, Goldey, & Kuo, 2011), derived from social neuroendocrinology, examines hormone responses to social contexts, and takes both sex and gender seriously. For example, the S/P theory details how empirical evidence supports linking high and low testosterone, not to masculinity and femininity but instead, to “competition” and “nurturance”—in women and men (van Anders, 2013; van Anders et al., 2011). Briefly, nurturance refers to warm, loving contact; competition refers to access to or defense of resources (e.g., power, sexual pleasure, financial resources, etc.). How does the S/P theory invoke culture? Well, women and men are differentially socialized to competition and nurturance; for example, girls are barred from football while boys are discouraged from babysitting. How might a lifetime of socialization towards or away from competition or nurturance affect hormone levels? Accordingly, social neuroendocrinology also uses or evokes the term “gender/sex,” which is useful for evolutionary theorizing; it specifically highlights that all humans are simultaneously evolved and sociocultural beings (van Anders, 2013). And, gender/sex can be useful for generating hypotheses about “tricky” results that defy conventional hormone-behaviour associations, like sexual desire.
Testosterone is positively correlated with solitary desire in women, but negatively with dyadic desire (van Anders, 2013). How can this be? Research on gender norms shows stigmatization of women’s sexual desire and pleasure, and the normativity of women not experiencing orgasm within heterosexual sexual encounters (Petersen & Hyde, 2011; Wade, Kremer, & Brown, 2005). Research rooted in social neuroendocrinology shows that sexual desire is multifaceted, and the S/P theory is useful for understanding that dyadic sexual desire might be nurturant for many heterosexual women because it is negatively correlated with testosterone, and also because women’s genital pleasure is not necessarily a likely outcome of this desire.
Partner cuddling is also “tricky”; it increases testosterone despite cultural expectations that it is nurturant and feminine. Yet, using predictions derived from the S/P theory, results show that partner cuddling is actually experienced as quite erotic (van Anders, 2013). Social neuroendocrinology thus provides insights into the evolved social functions of these behaviors by attending to gendered social constructions; doing so provides the means to empirically solve theory–data inconsistencies that would otherwise remain evolutionary paradoxes.
Social neuroendocrinology is falsifiable: hormone responses to social behaviors inform behavioral classifications, which are then subject to convergent falsification attempts. Falsification is the hallmark of scientific theories. Wood et al. (2014) carefully note that their meta-analytic lack of support for menstrual shifts does not disprove the possibility of menstrual shifts. But, if their meta-analysis is not a falsification, what is? And if menstrual shift science cannot be falsified, what type of science is it?
The study of evolved human biology is necessarily sociocultural, because human biology is socially situated. In other words, all human biophenomena occur in bodies that reflect both evolutionary and sociocultural processes. This understanding is the norm in contemporary bioscience including social neuroendocrinology but also epigenetics, social determinants of health, neuroplasticity, early life effects, etcetera. Incorporating sociocultural considerations allows evolutionary researchers to do research that does not end up, as Wood et al. put it: “missing some of the most important, characteristically human, evolutionary processes” (2014, p. 245).