Fatherhood lowers levels of testosterone

Chicago: Fatherhood lowers testosterone levels, US researchers said they have confirmed, making it easier for men to be involved in raising children. High levels of the hormone can rev up a man's sex drive, increase risk-taking behaviour and raise the need for social dominance. Those factors can help win a mate but are poor traits when it comes to raising a baby.

"Our study shows that human fathers are biologically wired to help with the job," said Christopher Kuzawa of Northwestern University, who worked on the study published in the Proceedings of the National Academy of Sciences.

Previous studies have shown fathers tend to have lower testosterone than men who have no children but it was not clear whether fatherhood was the cause or that men with lower testosterone were more likely to become fathers.