US dads of newborns are greying—percentage over 40 doubled since the 70s

(credit: Donnie Ray Jones)

Just like moms, American dads are getting older, according to a new study. Sadly, there’s no data suggesting their jokes are getting funnier, though.

Between 1972 and 2015, the mean age of US fathers crept up 3.5 years, from 27.4 to 30.9. The percentage of dads in their 40s more than doubled, from 4.1 to 8.9 percent. Likewise, fathers 50 and above jumped from 0.5 to 0.9 percent. And the uptick in greying pops appeared across all races, education levels, and regions.

The study, led by Stanford researchers and published this week in Human Reproduction, offers the most extensive look at paternal data yet, harvesting dad data from nearly 169 million birth records over the four decades. And the researcher's finding of across-the-board aging papas is a mixed bag, they write.