Baby cries and nurturance affect testosterone in men.

Testosterone (T) is generally theorized within a trade-off framework that contrasts parenting and low T with competitive challenges and high T. Paradoxically, baby cues increase T, prompting questions of whether T or its behavioral expression has been mischaracterized. We tested 55 men using a novel interactive infant doll paradigm, and results supported our hypotheses: We showed for the first time that baby cries do decrease T in men, but only when coupled with nurturant responses. In contrast, baby cries uncoupled from nurturant responses increased T. These findings highlight the need to partition infant cues and interactions into nurturant versus competitive-related contexts to more accurately conceptualize T, as per the Steroid/Peptide Theory of Social Bonds. This experiment also supports the utility of this paradigm for studying effects of infant interactions on hormonal responses, which may provide critical insights into ameliorating the darker sides of caregiving (e.g. anger, frustration, violence) and enhancing the positive sides (e.g. intimacy, nurturance, reward).