Researchers behind a new study showing that fathers experience a drop in testosterone when they tend to their children maintain that it proves men are biologically designed for childcare. They say that is a reassuring message. But one could just imagine legions of current and potential fathers wincing when they read the news. One could also envision wives, who already bear the greater burden of child-rearing, thinking, "Please don't let him see this."
In fact, the researchers overreached in interpreting the study results, but the data nonetheless are good news for the whole family, dads included. They suggest that a man's level of testosterone, which promotes muscle and hair growth and has been associated with aggression and risk-taking, can fluctuate according to his needs, including the need to raise a child. That doesn't prove nature intended for men to be active parents, but it does mean they can be good at the job if they choose it.
Like previous studies, the research, conducted by Northwestern University investigators on 624 men in the Philippines, indicated that men with higher levels of testosterone are more successful at mating. This was the first research to show that when men became fathers, their testosterone levels fell. The more time they spent with their kids, the less they had, and fathers of newborns had especially low levels of the stuff. Over a four-and-half-year period, men who became partnered fathers experienced a 34 percent drop in testosterone in the evening, compared with a 14 percent decline among single nonfathers. Still, the dads measured within normal ranges.
Other studies have established that partnered men and fathers have better health than comparable, single men. The Northwestern researchers think reduced testosterone during prime reproductive years may play a part. Higher testosterone is thought to be a risk factor in a number of health conditions, including prostate cancer.
When it came to drawing a larger meaning from their findings, the study's authors, in comments to the media, got political, marching headlong into the gender wars with pronouncements that here was evidence man was designed to change diapers and tell bedtime tales. Fathers should do those things, but this was not that proof.
Rather, the study showed that evolution equipped fathers with an appropriate biological response to parenthood. Consider that humans are equipped to build muscle mass when their bodies are tested by physical exertion. That does not mean people are designed to be manual laborers.
In figuring out who we want to be as individuals and as a society, it's valuable to know how we're built and where we come from, but it's not the whole story. Unique among the species of our planet, we get to choose. Whether or not nature intended it, fathers should tend their children. Mothers need more help at home, and kids deserve all the care they can get.
(Lisa Beyer is a member of the Bloomberg View editorial board.)