London, Aug 16 (IANS): Levels of the "cuddle chemical oxytocin" rise in new fathers to help them bond well with their babies. Fatherhood also triggers a surge in prolactin, a hormone more commonly linked to milk output in new mothers.

Both hormones were believed to help mother and baby bond. But they seem to benefit men too, suggests new studies, reports the Daily Mail.

Professor Ruth Feldman of the Bar-Ilan University, Israel, said: "This seems to be evolution's way of helping men turn into good parents as soon as they have a baby."

"These hormones seem to have a powerful role in helping men bond with their newly-born children," he added.

Feldman studied levels of the two hormones in new fathers in the six months after the arrival of their first.

The men were also filmed cuddling and playing with their kids, showing strong linkage between hormone levels and how good they were at playing and communicating with their babies.

It is believed that in the months after becoming a father, the hormones rewire men's brains, steeping them in greater empathy.

Writing in the journal Hormones and Behaviour, the professor said: "It is possible that, as the father's daily encounters with his infant increase... the prolactin and oxytocin systems reorganise and create new connections."

This could go some way to explain why some men appear to be reformed personalities after having children.