Good thing today’s my birthday

I could’ve been a whole lot dumber had I been born three months later. That’s what research keeps proving, apparently. Winter birth is a serious detriment to a child’s future health and brain power. From lacking vitamin D to when we start school, everything is affected by it. I got to start school when I was four. Well, Kindergarten. My birthday fell so close to the start of the school year anyway, so they let me start with the kids who’d already turned five. Did that really make enough of a difference? Had I started a year later, I wouldn’t have had my annoying cousin in my class, though. But then I would have been mocked for starting school late, rather than for everything else he found to tease me about. I think that definitely would have changed my attitudes and behaviours. Better it was done this way, me thinks.

I can’t speak for my mother’s family much since I don’t know any birthdays besides hers (August), but Dad (June) has several siblings born in January and February. In a farm family in the late 1930s and ’40s, though, it made a lot of sense to have winter babies. Grandma would have been needed a lot more in the kitchen during seeding and harvest than she would during calving, for one thing. Hard to be a gung-ho gardener/canner with a giant belly in the way.

Anyway, a couple University of Notre Dame economists were doing separate research on economics and families with children and each came up with similar conclusions.

In 2007, Mr. Hungerman was doing research on sibling behavior when he noticed that children in the same families tend to be born at the same time of year. Meanwhile, Ms. Buckles was examining the economic factors that lead to multiple births, and coming across what looked like a relationship between mothers’ education levels and when children were born.

“I was just playing around with the data and getting an unexpected result,” Ms. Buckles recalls of the tendency that less educated mothers were having children in winter.

Being colleagues, they got a chance to compare notes and were intrigued by each other’s findings.

If winter babies were more likely to come from less-privileged families, it would be natural to expect them to do more poorly in life.

The two economists examined birth-certificate data from the Centers for Disease Control and Prevention for 52 million children born between 1989 and 2001, which represents virtually all of the births in the U.S. during those years. The same pattern kept turning up: The percentage of children born to unwed mothers, teenage mothers and mothers who hadn’t completed high school kept peaking in January every year. Over the 13-year period, for example, 13.2% of January births were to teen mothers, compared with 12% in May — a small but statistically significant difference, they say.

Weird, eh? Exactly why this would be the case is still up in the air and open for debate, but it’s still interesting research.