A new study shows that it’s not only women’s bodies that adapt to parenthood: fathers who sleep next to their tot show dips in their levels of testosterone, which researchers say is good for baby.
In prior research, the study author and his colleagues found that when men become fathers, their testosterone levels drop — and the more involved dads were in caring for their children, the bigger their drops in the hormone.
In the new study, published online in the journal PLoS ONE September 5, Gettler and his colleagues analyzed data from more than 360 fathers in the Philippines, where sharing a bed with children is common practice.
After taking saliva samples before and after sleep, they found those who shared a bed with junior had dips in their testosterone levels in the evening. The researchers also took testosterone samples in 2005 and 2009 and they found that dads who dozed next to their child had a third less testosterone than before, compared to dads who slept separately.