Biological correlates of human male reproductive strategies and behavior

Abstract

Studies suggest that men’s genotypes and endogenous hormones interact with their contextual environment to influence mating decisions and paternal behaviors. Participants, 20-45 year old men, responded to questionnaires and gave blood samples before and after romantic and paternal caregiving interactions. The romantic setting included viewing two video clips (with partner, if applicable). The paternal setting included caring for a RealCare baby doll. Questionnaire data included demographics, personal history, relationship status, etc. Hormonal data included enzyme immunoassay of testosterone (T), cortisol (CORT), oxytocin (OT), and vasopressin (AVP). Genotyping of receptor polymorphisms included sequencing for androgen receptor gene (AR-CAG), three single nucleotide polymorphisms (SNPs) of OXTR, one SNP for CD38, and two microsatellites for AVPR1A. Chapter 1 results support the hypothesized 3-Group model with men in the Bachelor Group reporting demographic data consistent with short-term mating strategies and higher baseline T levels than men in the other two groups. Men in the Provider Group exhibited a mix of short-term and long-term mating strategies, whereas men in the Direct Father Group generally exhibited long-term mating strategies. Chapter 2 results indicated that OT levels were higher in men that spent more time with children and men in the Provider group. Higher OT levels in the Provider group were specific to particular recessive homozygous genotypes: OXTR 2254298 (GG > AA/AG), OXTR 53576 (GG > AA/AG) and CD38 (CC > AA/AC). Most interestingly, men in the Provider group experienced an increase in OT levels following the video session, but a decrease following the baby doll session. Chapter 3 results showed decreases in CORT levels during the baby doll session, and men in the low parent group of the RS/RS model experienced greater increase in ratios of OT levels. Although CORT levels declined in the baby doll session, different groups of men varied in the extent of decrease relative to other hormones. These study results will help inform public education of parenting support and potential interventions in instances of pathology, such as paternal abuse or neglect.