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For men hunting for a partner, testosterone’s a good thing. It boosts competitive behavior, and increases men's attractiveness to women. But the hormone has its drawbacks. Men with more of it have more marital problems and divorces. One study even suggested that guys with high testosterone have less sympathy for crying infants.
But there’s good news. Because having a kid appears to cut testosterone levels—essentially priming men to be better dads. So says a study in the Proceedings of the National Academy of Sciences. [Lee Gettler et al., "Longitudinal evidence that fatherhood decreases testosterone in human males," PNAS 2011]
The researchers sampled testosterone levels of over 600 21-year-olds in 2005, and again in 2009. And they quizzed them on their relationships in the interim.
Single guys with high testosterone had better luck finding mates by the study’s end, and were more likely to have become fathers. But their testosterone plunged, compared to peers who stayed single. And the more hours a day they spent with their kids, the lower their testosterone levels fell.
Which suggests that being a nurturing dad may have ancient evolutionary roots—and that men are biologically wired to shift from alpha-male to tender caregiver when bringing up baby.
—Christopher Intagliata
[The above text is a transcript of this podcast.]
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11 Comments
Add CommentDoes the study say anything about the weight change of those males?
Reply | Report Abuse | Link to thisMore one spends time with the kids,
less exercise >> body fat up >> testosterone down
That only applies for American Dad's as in England for Example.. a lot of Dad's cycle either towing their children or on a baby chair...
Reply | Report Abuse | Link to thisThere are two problems with the reporting of the findings of this study: (1) causality (Baby Makes Daddy Lose Testosterone)does not necessarily follow; and (2) there could be other explanations for the reduction in testosterone before and after the birth of the baby (there is no control group with which to compare that reduction).
Reply | Report Abuse | Link to thisIsn't the single guys from the group the "control" group?
Reply | Report Abuse | Link to thisLet me say what I meant to say: There are other things occurring around the time of the birth of the baby other than the birth itself. This was not a true experiment with random assignment to have or to not have a baby (as that is at least unethical), so the single guys are not a very good control, since the sorts of things that might be contemporaneous for them might not be the same sorts of things that are contemporaneous for the father-to-be.
Reply | Report Abuse | Link to thisDoes that help?
What's needed is a control group of men with children that didn't stay near the children.
Reply | Report Abuse | Link to thisAlso, low testosterone is a predictor of lowered life expectancy as well. This study "suggests" all sorts of things.
I wonder if it makes a difference if:
Reply | Report Abuse | Link to this- kids are adopted as babies
- the adopters are gay males - in that case, would BOTH males show this tendency? That surely must be easy enough to track?
Someone has suggested pheronomes as the actual trigger. From the mother. What I've just read suggests it may be the baby that provides the trigger - chemical?
Causality is an issue. Maybe men actually fair better if they maintain higher levels of testosterone. It would be interesting to know if high testosterone divorced males ultimately have more children than lower testosterone males. Divorce would free high testosterone males to find other cooperative females with which to reproduce again.
Reply | Report Abuse | Link to thisSo, what happens once the child matures or leaves the nest? Do testerone levels rise?
Reply | Report Abuse | Link to thisDo not elevated testosterone levels increase cancer risk? Testicular cancer tends to be a youg mans' disease. How do low levels of testosterone indicate decreased life expectancy? What is the source of this information?
Many questions here relating to methodology and conclusions need clarification.
terrific
Reply | Report Abuse | Link to thisLess exercise because of kids? Mine always guaranteed weight loss, at a young age (theirs and mine) because of Play (which we guys seem to do better, at least we do something right) and The Rest of It. Now, as one of them has kids and the other doesn't, both still manage to cause me total anxiety and then .... there's Danny and Sophia whose demands centre on play and attention and joining in activity make such ideas wholly unsustainable.
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