Size Matters? Testicle Size Linked To Nurturing

dad_baby_2013Men with smaller testicles are more likely than their well-endowed brethren to be involved in the care of their toddlers, anthropologists at Emory University report.

The higher the testosterone levels and larger the testicles, the smaller the amount of direct paternal caregiving by dads as reported by parents in the study.

“Our data suggest that the biology of human males reflects a trade-off between mating and parenting,” Emory anthropologist James Rilling, whose lab conducted the research, reports on the Atlanta university’s website. The Proceedings of the National Academy of Sciences published details of the study this week.

The goal of the research, Rilling says, was to determine why some fathers work harder at parenting than others. “Previous studies have shown that children with more involved fathers have better social, psychological and educational outcomes,” he told the school’s website.

Rilling noted that “life history theory” holds that evolution optimizes use of resources toward mating or parenting to generate the largest number and healthiest offspring.


Source: USA Today