The causal effect of testosterone on men's competitive behavior is moderated by basal cortisol and cues to an opponent's status: Evidence for a context-dependent dual-hormone hypothesis

Abstract

Testosterone has been theorized to direct status-seeking behaviors, including competitive behavior. However, most human studies to date have adopted correlational designs, and findings across studies are inconsistent. This experiment (n = 115) pharmacologically manipulated men's testosterone levels prior to a mixed-gender math competition and examined basal cortisol (a hormone implicated in stress and social avoidance) and context cues related to an opponent's perceived status (an opponent's gender or a win/loss in a prior competition) as factors that may moderate testosterone's impact on competitive behavior. We test and find support for the hypothesis that testosterone given to low-cortisol men evokes status-seeking behavior, whereas testosterone given to high-cortisol men evokes status-loss avoidance. In the initial rounds of competition, testosterone's influence on competitive decisions depended on basal cortisol and opponent gender. After providing opponent-specific win-lose feedback, testosterone's influence on decisions to reenter competitions depended on basal cortisol and this objective cue to status, not gender. Compared to placebo, men given exogenous testosterone who were low in basal cortisol showed an increased tendency to compete against male and high-status opponents relative to female and low-status opponents (status-seeking). Men given exogenous testosterone who were high in basal cortisol showed the opposite pattern-an increased tendency to compete against female and low-status opponents relative to male and high-status opponents (status-loss avoidance). These results provide support for a context-dependent dual-hormone hypothesis: Testosterone flexibly directs men's competitive behavior contingent on basal cortisol levels and cues that signal an opponent's status. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Figure 1.

Theoretical model of a context-dependent dual-hormone hypothesis for testosterone’s effects on competitive behavior. References in figure: 1) Mehta & Josephs, 2010; 2) Mehta & Prasad, 2015; 3) Sarkar et al., 2019; 4) Knight et al., 2020; 5) Dekkers et al., 2019; 6) Knight & Mehta, 2017; 7) Marceau et al., 2015; 8) Turan et al., 2015. See Knight et al. (2020) for a broader review.

Figure 2.

The Competition Task Note. (A) In the early rounds of the competition task, participants made decisions to enter competitions against 16 opponents (n = 8 females) or play for a piece rate instead. Participants also played in 16 mandatory compete and 16 mandatory piece-rate rounds against the same opponents (48 rounds in total). The actual competition consisted of answering as many True/False equations as possible within 10 s. Scores in a given competition trial were compared to the opponent’s actual score on the same set of True/False equations. (B) After completing all 48 rounds, participants were provided feedback from the 16 mandatory compete rounds and asked whether they wanted to compete against that opponent again (“Replay”) or play for a piece rate instead. One of these decisions was randomly selected to be played. Opponent images in this figure were not part of the stimuli but are representative of the types of photos in the opponent pool. The numbers appearing in the upper left corner of each frame are included to be able to describe the task and were not part of the task.

Figure 3.

Estimated marginal means of main effects of key study variables on probability of choosing to compete. Charts in left column are from decisions to enter competitions in the Initial Phase; charts in right column are from Feedback Phase decisions to re-enter competitions. *indicates 95%CI of difference does not contain zero.

Figure 4.

Estimated Marginal Probability of Choosing to Compete as a Function of Testosterone Treatment, Basal Cortisol, and Social Contextual Factors Note. All values on every panel are derived from the main analytical models (e.g., estimated marginal means or simple slopes). Error bands represent 95% CI of model estimates. Panels A and C represent the full range of basal cortisol values, whereas the simple slope analyses in text and Panels B and D present results from ±1 and 2 SD. For illustrative purposes and to better match the prior literature, the probabilities calculated from simple slope logits extracted from the three-way interaction were inverted, that is, “1 − p(Compete),” in Panels B and D. (A) Probability of choosing to enter competitions from the initial phase, conditional on the gender of an opponent. (B) Probability of competing against female opponents versus male opponents for testosterone treatment and placebo groups at several basal cortisol levels. Positive values on this chart indicate that the probability to compete against male opponents is higher than competing against female opponents. (C) Probability of choosing to re-enter competitions after feedback, conditional on prior competitive outcomes. (D) Probability of competing after winning versus after losing for testosterone treatment and placebo groups at several basal cortisol levels. Positive values on this chart indicate that the probability of choosing to compete against a prior winner is higher than competing against a prior loser.

Figure 5.

Meta-analyses of testosterone × cortisol × opponent status in two studies. These figures depict Fisher’s z values. A) Fixed effects (FE) model with prior outcome as indicator of opponent status in the present experiment. B) Random effects (RE) model that includes both prior outcome and opponent gender as indices of perceived opponent status.