The case for dads

A new book explores the impact of fathers on their children's development, from roughhousing to vocabulary-building to teen pregnancy. We still have a lot to learn, Mark Oppenheimer reports.

When our young daughters first decided to play on top of our Honda minivan, parked in our driveway, my wife was worried. But to me, it seemed no less safe than chasing a ball that frequently ended up in the street. And they loved the height, the novelty, the danger. So I let them stay. They never fell. And with the summer weather here, playing on the car is once again keeping them occupied for hours.

Now that I have read Paul Raeburn's Do Fathers Matter?, I know that my comfort with more dangerous play - my willingness to let my daughters stand on top of a minivan - is a typically paternal trait. Dads roughhouse with children more, too. They also gain weight when their wives are pregnant and have an outsize effect on their children's vocabulary. The presence of dads can delay daughters' puberty. But older dads have more children with dwarfism and with Marfan syndrome.