We all know that having a baby can bring on some pretty dramatic hormonal changes for new moms, but who knew dad’s hormones were going a little haywire too? A new study shows that men’s testosterone levels go way down after becoming a dad.

The study, published in a recent issue of Proceedings of the National Academy of Sciences, shows that men who are more involved with caring for the new baby see an even greater drop in testosterone than those who shrug off diaper changes and midnight feedings.

It seems the younger the baby the lower a dad’s testosterone, with a whopping 50% decrease of the hormone in men with an infant under 1 month old. The study’s findings highlight a serious flaw in the popular notion that women are the only ones biologically predisposed to caring for children.

A CBS news report quotes co-author of the study, Dr. Christopher Kuzawa, explaining, “Classic models of human evolution emphasized the role of men as hunters and providers, with the assumption being that mothers were responsible for childcare. Our findings challenge this model by showing that human fathers also are wired to care for their children."

Researchers hope the study’s findings will help to erase the idea that men were meant to be the “hunters and gatherers” and women - the childcare givers.

What do you think of the findings that new fathers see a dramatic drop in their testosterone levels after the birth of their child?

Did your partner develop a new sensitive side after the birth of your child?