Date Published: June 5, 2018
Publisher: Springer International Publishing
Author(s): Jaimie S. Torrance, Amanda C. Hahn, Michal Kandrik, Lisa M. DeBruine, Benedict C. Jones.
Many previous studies have investigated relationships between men’s competitiveness and testosterone. For example, the extent of changes in men’s testosterone levels following a competitive task predicts the likelihood of them choosing to compete again. Recent work investigating whether individual differences in men’s testosterone levels predict individual differences in their competitiveness have produced mixed results.
In light of the above, we investigated whether men’s (N = 59) scores on the Intrasexual Competitiveness Scale were related to either within-subject changes or between-subject differences in men’s salivary testosterone levels.
Men’s responses on the Intrasexual Competitiveness Scale did not appear to track within-subject changes in testosterone. By contrast with one recent study, men’s Intrasexual Competitiveness Scale also did not appear to be related to individual differences in testosterone.
Our results present no evidence for associations between men’s testosterone and their responses on the Intrasexual Competitiveness Scale.
The online version of this article (10.1007/s40750-018-0095-2) contains supplementary material, which is available to authorized users.
Results of several studies suggest that increases in men’s testosterone levels due to competitive tasks are associated with increases in their intrasexual competitiveness (reviewed in Zilioli and Bird 2017). For example, men whose testosterone levels increased after competing against another man on a laboratory task (the Point Subtraction Aggression Paradigm, see Geniole et al. 2017 for a review of this method) were more likely to choose to compete again than were men whose testosterone levels did not increase after competing on the initial task (Carré and McCormick 2008). Similarly, the extent to which men’s testosterone increases after losing a competitive task against another man is positively related to their willingness to compete again (Carré et al. 2009; Mehta and Josephs 2006). These effects can be modulated by the decisiveness of the victory (Mehta et al. 2015a) and/or men’s aggressiveness (Carré and McCormick 2008).
The dependent variable was Intrasexual Competitiveness Scale score. Predictors were current testosterone, current cortisol, and their interaction, and average testosterone, average cortisol, and their interaction. No covariates were included in the model. Random slopes were specified maximally following Barr et al. (2013) and Barr (2013). Full model specifications and full results for each analysis are given in our Supplemental Information. Results are summarized in Table 1. There were no significant effects.Table 1Summary of results for men’s hormone levels and reported intrasexual competitivenessEstimateStd. ErrordftpCurrent testosterone0.0530.22738.2800.2350.815Current cortisol0.0940.21634.6200.4340.667Current testosterone x Current cortisol2.5651.566162.411.6370.103Average testosterone0.3890.64760.2900.6010.550Average cortisol−0.2210.86561.430−0.2560.799Average testosterone x Average cortisol−4.4213.02959.540−1.4600.150
Our analysis of men’s reported intrasexual competitiveness revealed no significant relationships between reported intrasexual competitiveness and men’s hormone levels. We found no evidence that within-subject changes in men’s reported intrasexual competitiveness tracked changes in men’s current testosterone, current cortisol, or their interaction. We also found no evidence that between-subject differences in reported intrasexual competitiveness were related to men’s average testosterone, average cortisol, or their interaction. These latter null results are noteworthy because they do not replicate Arnocky et al.’s (2018) recent finding of a positive correlations between reported intrasexual competitiveness and testosterone level.