Traditional masculinity ideology enhances testosterone reactivity in human fathers of preschoolers

The Challenge Hypothesis suggests that decreases in testosterone represents a shift in energetic resources toward more nurturing paternal behavior, and increased testosterone toward competitive mating behavior. More controversial theories have also suggested that elevated testosterone is related to more stereotypically "masculine" behavior. Parenting dynamics are heavily influenced by gender roles, but little research has examined how the proposed roles of testosterone and masculinity might interact in a parenting context. We measured salivary testosterone across 42 father-child interactions and analyzed how the father's traditional masculinity ideology was related to changes in testosterone across the lab visit, hypothesizing that higher traditional masculinity ideology would predict a smaller decrease in testosterone due to notions of caregiving as a traditionally "feminine" responsibility. Contrary to our hypothesis, testosterone declined more in fathers who reported higher alignment with traditionally masculine beliefs, and among those who did not identify as the child's primary caregiver. These findings contradict notions that greater masculinity is related to increased testosterone and suggest that the physiological responses observed during such interactions may be influenced by perceptual factors such as the novelty of the situation.