Testosterone and vasopressin in men’s reproductive behavior

One common practice used by researchers is to divide human reproduction into two major domains: mating and parenting. Adaptive problems men faced over the millennia may have produced evolutionary pressure for hormone responses and behavior that facilitate both mating and parenting, either separately or simultaneously. The sometimes competing domains of mating and parenting in men are often mediated by a number of the same hormones, such as testosterone (T) and arginine vasopressin (AVP). One aim of the current study was to examine differences in baseline levels of T and AVP between childless men who were not in an exclusive, romantic relationship and married fathers. Another aim was to examine differences in responses in these hormones as a function of relationship/parental status and mating versus parenting audiovisual stimuli. Sixty men, ages 21-44 years, completed the study. Thirty were single, childless men and 30 were fathers, 29 of whom were married. Participants provided saliva samples for T assay and urine samples for AVP assay before and after viewing one of two randomly assigned 15-minute videos. One video was aimed at mating efforts and included couples engaging in sexual activity. The other video was aimed at parenting efforts and included clips of babies/toddlers crying from receiving a vaccination needle. There was no significant difference in baseline T or AVP between the single, childless men and the married fathers. Also, there was no significant difference in T or AVP responses as a function of relationship/parental status or video condition. Interpretation of the results and conclusions are discussed