Mother Nature ensures fathers don’t stray from home

IN what may seem like news to women everywhere, a study has found that men are less likely to stray after having children because fatherhood lowers testosterone.

Apparently, it is nature’s way of ensuring the male stays at home and contributes to child care.

Testosterone is the male hormone that increases sex drive and drives men to compete for mates. But once they become fathers, macho mating activity may conflict with parental responsibilities.

Lowering testosterone is likely to make a man a better father by helping to bring out his nurturing feminine side, the study suggests. Scientists followed a group of 624 men aged 21 to 26 for over four years and measured their testosterone before and after they became fathers.

Fatherhood for partnered men typically reduced testosterone by 34%.

“It’s not the case that men with lower testosterone are simply more likely to become fathers,” said researcher Lee Gettler, from Northwestern University in Illinois, US.

“On the contrary, the men who started with high testosterone were more likely to become fathers, but once they did, their testosterone went down substantially.”

The study, conducted in the Philippines, showed men with babies less than a month old had especially reduced levels of testosterone. Larger falls were seen in those more engaged in childcare.

“Humans are unusual among mammals in that our offspring are dependent upon older individuals for feeding and protection for more than a decade,” said study co-author Christopher Kuzawa. “Raising human offspring is such an effort that it is co-operative by necessity, and our study shows that human fathers are biologically wired to help with the job.”

The research is published in the journal Proceedings of the National Academy of Sciences.