Pair Bonding and Testosterone in Men: Longitudinal Evidence for Trait and Dynamic Associations

The role of exogenous testosterone and social environment on the expression of sociosexuality and status-seeking behaviors in young Chilean men

Testosterone plays an important role as a social hormone. Current evidence suggests that testosterone is positively related to sociosexuality increasing the psychological attitudes toward investing in short-term versus long-term mating and promotes status-seeking behaviors both by dominance and prestige. In addition, the social environment may play an important role in the expression of mating effort through changes in sociosexuality and status-seeking behaviors. However, the causal relationships among the mentioned variables are still debated. We employed a double-blind, placebo-controlled within-individual design, in order to test and integrate the proposed causal relationships between testosterone and social environment over short-term and long-term mating orientation and dominant and prestigious status-seeking behaviors in a sample of 95 young Chilean men. We did not find evidence that the administration of exogenous testosterone increased short-term or decreased long-term mating orientation as expected. Moreover, exogenous testosterone did not affect either aggressive or cooperative behavior failing to support the social status hypothesis. We also did not find any relationship between short or long-term mating orientation with status-seeking behaviors. Finally, we found support for the effect of social environment on sociosexual attitudes but not over status-seeking behaviors. Thus, men reported higher levels of short-term mating orientation in the presence of a woman compared to a man and no differences were found for long-term mating orientation. We argue that sociosexuality may be expressed flexibly, but contextual factors such as the presence of women seem more important than changes in testosterone levels.

Human reproductive behavior, life history, and the Challenge Hypothesis: A 30-year review, retrospective and future directions

The Challenge Hypothesis (Wingfield et al., 1990) originally focused on adult male avian testosterone elevated in response to same-sex competition in reproductive contexts. The purpose of the present paper is to demonstrate how the Challenge Hypothesis has shaped ideas about human life histories. We conduct a citation analysis, drawing upon 400 Google Scholar citations in the human literature to identify patterns in this body of scholarship. We cover key factors, such as context and personality traits, that help explain variable testosterone responses such as winning/losing to adult competitive behavior. Findings from studies on courtship and sexual behavior indicate some variation in testosterone responses depending on factors such as motivation. A large body of research indicates that male testosterone levels are often lower in contexts of long-term committed partnerships and nurturant fathering and aligned with variation in male mating and parenting effort. As the Challenge Hypothesis is extended across the life course, DHEA and androstenedione (rather than testosterone) appear more responsive to juvenile male competitive behavior, and during reproductive senescence, baseline male testosterone levels decrease just as male life history allocations show decreased mating effort. We discuss how research on testosterone administration, particularly in older men, provides causal insight into effects of testosterone in humans, and how this "natural experiment" can be viewed in light of the Challenge Hypothesis. We synthesize central concepts and findings, such as an expanded array of costs of testosterone that inform life history tradeoffs between maintenance and reproductive effort, and we conclude with directions for future research.

Average Associations Between Sexual Desire, Testosterone, and Stress in Women and Men Over Time

Sexual desire and testosterone are widely assumed to be directly and positively linked to each other despite the lack of supporting empirical evidence. The literature that does exist is mixed, which may result from a conflation of solitary and dyadic desire, and the exclusion of contextual variables, like stress, known to be relevant. Here, we use the Steroid/Peptide Theory of Social Bonds as a framework for examining how testosterone, solitary and partnered desire, and stress are linked over time. To do so, we collected saliva samples (for testosterone and cortisol) and measured desire as well as other variables via questionnaires over nine monthly sessions in 78 women and 79 men. Linear mixed models showed that testosterone negatively predicted partnered desire in women but not men. Stress moderated associations between testosterone and solitary desire in both women and men, but differently: At lower levels of stress, higher average testosterone corresponded to higher average solitary desire for men, but lower solitary desire on average for women. Similarly, for partnered desire, higher perceived stress predicted lower desire for women, but higher desire for men. We conclude by discussing the ways that these results both counter presumptions about testosterone and desire but fit with the existing literature and theory, and highlight the empirical importance of stress and gender norms.