Do First Born Kids Have Higher IQs?

Dear Isabelle,

Well, your sister is right -- but she doesn't have the whole story.

Many studies over the years have found a small but significant IQ gap between first born kids of either gender and their younger siblings. The most recent, a large and well-designed Norwegian study, claims that oldest children as a group are three IQ points smarter than their next-eldest brothers, who are in turn a bit smarter than those younger.

Previous explanations for the IQ gap focused on the observation that parents are free to lavish more attention on their first born until more children arrive, as well as the hypothesis that oldest kids are brought up to be more responsible and hard-working. All parents know that we worry more over the first baby, and impose higher standards.

The Norwegian researchers, however, offer a novel but intriguing theory: oldest children are in the position of teaching their siblings and showing them how to do things. They may get more out of that tutoring than the recipient does.

I don't think your younger kids will be handicapped in life. Here's my advice:

1. RELAX! This is not that big a deal. How you listen to your child on a daily basis, how you set limits (with empathy, I hope), how much you read to your child -- all these things will have much more impact on his success in life than three IQ points. And if you're pregnant, you should know that breastfeeding your baby will increase her IQ by 5 points, according to a huge and comprehensive study published in the American Journal of Clinical Nutrition, involving 11 different studies and over 7000 children.

2. Encourage informal tutoring by BOTH older and younger kids, each providing leadership in things they're better at. If one on one tutoring doesn't make sense, encourage kids to “teach” at the dinner table. Every child is knowledgeable about something. Or arrange for younger siblings to tutor kids at school.

3. Other than breastfeeding, the best way for parents to raise a child's IQ is by reading to him and limiting TV. That will more than make up for any birth order impact.

4. EQ, or Emotional Quotient, is arguably more important in life achievement than a few points of IQ , and definitely more important in happiness ratings. High EQ means being better able to manage one's emotions and anxiety, being more aware of one's own and other's feelings, and having better interpersonal skills. Because parents are less anxious with their second child, younger siblings are generally better able to manage anxiety. They are also generally recognized as having better interpersonal skills. Therefore, they probably have higher EQs, and may well out-perform those with slightly higher IQs.

5. Having slightly higher IQs may not make it worth the stress of being first-born. The study apparently found that oldest kids run a higher risk of becoming alcoholics and substance-abusers. First-borns need parental encouragement to relax and be themselves, so they don't bear the full weight of the parents' neuroses.

6. Several studies have demonstrated that specific personality traits such as conscientiousness and openness to experience are up to 10 times more important than IQ (Sulloway, 1996) For example, a scientist who has an IQ of 130 is just as likely to win a Nobel Prize as a scientist whose IQ is 180 (Hudson, 1966, p. 104, cited in Sulloway, p. 357). Personality traits and EQ are what make the difference.

7. Family size and spacing of kids has more impact than being first born. The more kids in a family, the lower the kids' IQs are likely to be. And if you space any of your kids closer than two years apart, that's a risk factor for not having a solid bond with either child, which lowers EQ as well as IQ.

8. This IQ difference is not as big a deal as your sister (and prior news reports) make it out to be. Not to get too technical, but the study found that firstborns as a group have a 3 pt lead in IQ, not that individual firstborns are smarter than their siblings. According to Mark Liberman of Language Log, that only means “the first-born will have a higher IQ about 55.6% of the time. And therefore will lose the IQ contest about 44.4% of the time.”

So enjoy your children, whatever their birth order. They'll be fine!