On the research and its findings
"There's long been this idea that older and younger siblings have certain characteristics, that might be explained by genetics or environment. The stereotype, I think, has been that older siblings are a little bit smarter, a little bit more organized, and younger siblings are a little more wayward, or more experimental. This study, which looked at registry data of Swedish men, found that yes, indeed these stereotypes do hold up in the data. Firstborn children are 30 percent more likely to be top managers, later-born children are much more likely to be self-employed. Older siblings tend to be more natural leaders, they have more leadership ability, more social ability, than their younger siblings."
On what prior research has revealed about firstborn children
"International surveys seem to find that firstborns around the world have higher IQs, they perform better in school, they're considered more accomplished by their parents. And in case you're thinking, 'Well that's just their parents' evaluation,' well no, even when researchers evaluate them, firstborns tend to have higher educational attainment, higher earnings. They stay in school longer, they earn more. They even have higher IQ. They're likely to be healthier. And this study that looked at Swedish registry data found that it's not just the cognitive abilities that decline with birth order, it's non-cognitive abilities, too — firstborns seem to be more emotionally stable, and as I said, have better leadership ability. So across the board, really, it found a lot of advantages to being a firstborn child."
On theories behind the advantages of being a firstborn child
"There are a lot. And let me boil it down into two words: attention and competition. Attention is the idea that earlier-born siblings enjoy more time, care and attention than later-born siblings, simply because attention for later-born siblings is divided between fewer kids. It's possible that the parents themselves just get a little bit lazy, that they sort of, they have the first child, they buy 100 books, they're freaked out about making sure that it turns out perfectly, they commit to memory the first chapter of 'Battle Hymn of the Tiger Mother.' But by the second or third child, they've sort of chilled out a little bit, they feel like they know how to do this.
"The second theory, though — which I find really interesting, and sort of economic in a way — is a theory of competition. It's this idea that older and younger kids play specific roles in the family, and older siblings often have to teach their younger brothers and sisters how to behave, and this sort of instills in them a sense of leadership. Younger siblings, however, have to compete a little bit more for their parents' attention. By definition they're competing amongst lots of children. And as a result, they have to learn how to be a little bit more sociable, a little more easygoing, a little more innovative about filling that niche. And as a result, they might be more likely to go into self-employed occupations, rather than clear leadership roles."
On the implications for children as they grow up
"I think the implications here are sneakily profound. We know that children have what developmental psychologists sometimes call a 'sensitive period,' were they are extremely sensitive to their environments. This is true for exposure to lead, it's true for the impact of divorces among young kids, on violence in neighborhoods with young children. That when we're extremely young, we are unbelievably sensitive to our environments, and that that sensitivity can play an enormous role on how we behave later in life: the occupations we go into, the amount of money that we make, the sort of people that we become, the personalities that we develop. And so it seems like simply having an older brother, or having a younger sister at the age of 4, 5, 6, might make an enormous difference on sort of interpersonal intelligence, how we see ourselves in the world and the niche we try to make of it."
This article was originally published on May 08, 2017.
This segment aired on May 8, 2017.