The “dad bod” isn’t the only physical change new fathers have to deal with, says Dr Anna Machin in The New York Times. Testosterone – the “male” hormone that motivates men to find sexual partners – crashes. You’ve done your mating, says the body: now it’s time to stop all that and look after the family. News of this drop is often greeted with “groans of resignation” from men. Choose fatherhood, they think, and choose the “road to emasculation”. But the lower your testosterone, the more likely you are to release the “reward and bonding” chemicals oxytocin and dopamine when you play with your child. This produces feelings of happiness, contentment and warmth – “a welcome trade-off”.
When scientists put new dads in an MRI machine, they found the same structural changes to the brain we’ve long known about in mums: areas linked to attachment, nurturing and empathy had physically grown. The changes aren’t the same for both sexes: women are rewarded more for nurturing, men get a bigger boost from “rough and tumble”. It’s not just a cliché that children run to mum for a cuddle, while dad is the “fun” one. Turns out it’s biology.
Don’t despair about a few grey hairs
Grey hairs can return to their original colour, says Diana Kwon in Scientific American. A new study suggests that the greying process is closely linked to stress levels – and can be reversed in periods of calm. One 35-year-old man involved saw five grey hairs revert to auburn on a two-week holiday. While this is good news for 30-year-olds with their first silvery strands, it’s presumed that older people with a full head of grey hair have reached “a point of no return”.