Longitudinal Perspectives on Fathers’ Residence Status, Time Allocation, and Testosterone in the Philippines

Past paternal psychobiology research has focused almost exclusively on biological, residential fathers and the role of fathers as direct caregivers. Here, drawing on a large sample of Filipino men, we help to expand this research area by testing for relationships between fathers’ testosterone, prolactin, and weekly hours in work, childcare, and recreation. Using longitudinal data collected when men were an average of 21.5 and 26.0 years old, we tested whether changes in fathers’ investments in childcare and work interrelated with testosterone changes. We also assessed whether fathers’ residence status affected paternal testosterone changes. Cross-sectionally, we did not find evidence that fathers’ testosterone or prolactin varied based on work effort or weekly hours of childcare (all p > 0.1). Fathers who increased their weekly involvement in childcare between baseline and follow-up experienced declines in testosterone, on average (p < 0.05). Men who transitioned from being non-fathers (baseline) to being new fathers residing with their children (follow-up) experienced significantly larger declines in both waking and evening testosterone, compared to men who were residential fathers at both time points (both p ≤ 0.0001). Men who became new fathers but were not residing with their children also showed significantly greater declines in evening testosterone, relative to the comparison group (p < 0.05). Our results add confirmation and expansion of the notion that low paternal testosterone is linked to heightened father-child interaction and proximity, but leave open the possibility that fatherhood can also affect men’s testosterone independent of whether they reside with their children.