FULLTITLE: Why fathers are faithful: Becoming a dad causes a testosterone drop that makes men less likely to stray They say having a family changes a man for ever. But it may not just be a sense of duty that drives new dads to swap evenings in the pub for quiet nights at home. Scientists have discovered fatherhood can halve testosterone levels – and stop men from straying. A study has found that when men become fathers, their bodies suppress production of the sex hormone, making them more interested in parenting than mating. American researchers studied more than 600 men...
