The Acutely and Socially Sensitive Testis: New Human Data and an Evolutionary Perspective
, , , , , and (University of Nevada, Las Vegas)
The rapid ability of vertebrate male testosterone levels to respond to social stimuli, such as male competitors and potential mates, appears adaptive. Here, we sought to test several hypotheses concerning rapid, socially sensitive testosterone responses in men. Viewing music as an evolutionary important prime, we anticipated that listening to different types of music could differentially affect men’s testosterone and aggressiveness. In study 1, we recruited 30 men aged 19–55 years (mean = 26.4, SD = 9.3). Subjects completed a brief questionnaire, provided saliva samples (to measure testosterone) before and after listening to 15 minutes of music (either heavy metal or classical) and completed a brief behavioral test of aggression. Men’s testosterone levels increased by 30% during this brief experiment regardless of the type of music one heard. In study 2, we recruited 30 men aged 18–55 (mean = 24.6, SD = 7.8) who engaged in a similar protocol with two exceptions: these men interacted with a male experimenter (rather than a female experimenter as in study 1), and provided an additional third saliva sample 15 minutes after the second saliva sample. Results revealed that men’s testosterone levels increased by 38% from time 1 to time 2, did not change between times 2 and 3, and these changes were unrelated to the type of music to which a subject listened. We suggest that our sampling protocol elicited an acute male testosterone response stemming from brief interactions with women and men.