Thursday, June 28, 2007

Birth Order and IQ

There has been much discussion, the past few days, about a new Norwegian study showing that birth order affects IQ scores. Oldest sons tend to score higher on IQ tests than later sons, but the difference appears to be because of how children are raised, not biology. Later-born sons whose older brothers died in infancy show similar IQs to those who were first-born.

So what's to be made of this? Probably not much. The difference was 2-3 IQ points, which is pretty much meaningless. But that doesn't stop people from drawing whatever conclusions they like. I particularly laughed at the quote from the UC-Berkeley expert in the AP article I linked, above, stating that eldest children were probably smarter because they tutored their younger brothers and sisters. This idea that kids benefit from tutoring each other is often expressed in education circles, because it lets harried teachers use gifted kids as unpaid teaching assistants and claim it's good for them.

But anyway -- if I had to guess, I'd say the tiny difference is because parents have more time and energy to pay undivided attention to their first born children during the first 2 years of their lives. An acquaintance of mine recently confessed that with his first daughter, he was reading stories to her in the womb and, presumably, with even greater frequency after birth. The second daughter got no in-the-womb story sessions. Likewise, with my baby, I spend a reasonable amount of time showing him different patterns and objects, exposing him to different sounds, etc. I can't imagine doing as much of this if I had a 2-year-old shrieking around the house. But if that's the reason for the difference, the study's conclusion is heartening to me. If all that difference in time and energy only adds up to 2-3 IQ points, it would take a lot for good intentioned parents to really mess their children up.


Sfireblue said...

Laura wrote<< I'd say the tiny difference is because parents have more time and energy to pay undivided attention to their first born children during the first 2 years of their lives>>

I agree with that. After all, think of the photo albums! Chances are the one of the first born is a finished product done with care, whereas that of the second may still be a work in progress even when that child has reached his or her teens! :)

Cher Mere said...

Dear Laura

I was wondering if you could contact me. My email is

I see that you lived in South Bend and we are thinking of moving there with our PG daughter (also a Davidson Young Scholar) and I was hoping you could give me your perspective on the area.

Thank you

Bharathy said...

I agree with that.I had taught my first born the alphabet, numbers and poems when I was carrying him.I had named him before he was born and I can tell you he used to respond beautifully to his name.At 33 weeks,when I called out to him and he did not respond, I knew something was terribly wrong.When I slept in the afternoon, I almost heard him say that we would meet that night.I woke up and rushed with my mother to the doctor who confirmed my fear.We were given 2 hours and 30 % chance of survival and we succeeded.Since I was busy monitoring his physical milestones, I hardly discussed poems.At 12 months, I casually said "Jack and Jill went up the hill to fetch a pail of" and paused.Lo and behold, he clearly said "water" which was his first word.I gave him five years of my undivided attention (although full time working) and it made a lot of difference to him that someone knew from the start that he was different.My second son also had a vocabulary of 200 words in 4 languages at 16 months and is equally good but Senior has an edge over him...2-3 IQ points as u say.