This article was published in Scientific American’s former blog network and reflects the views of the author, not necessarily those of Scientific American
Bossy, know-it-all older sisters everywhere now have something else to lord over their younger siblings: Researchers have found that firstborn girls are the most ambitious and successful children in their families.
On supporting science journalism
If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.
A slew of real life examples appear to back this up: Beyonce, Hillary Clinton, Oprah Winfrey and Sheryl Sandberg are all firstborns. Oldest children are 16 percent more likely to excel academically than younger siblings, according to scientists from the University of Essex in the U.K.
This is especially true for girls: eldest daughters are an additional four percent more likely to go on to higher education than eldest sons—the next most successful sibling type.
The influence of birth order on personality has long intrigued social scientists, but earlier studies supporting the superiority of firstborns have been criticized for flaws in their methodology. For example, previous studies mostly looked at average effects derived from large groups of people, so they could have missed more nuanced dynamics at play—such as the numbers of brothers and sisters in each family and the age spacing between siblings.
Lead researcher Feifei Bu and her colleagues tried to overcome such issues in their analysis of data from a British survey of families containing 1,503 sibling groups and 3,552 individuals. They used a particular statistical model that allowed them to examine subtle differences within and between families to see if they were more important than birth order. (They weren’t.) In addition, the study excluded families with only one child and families with firstborn twins, whose unique experiences could skew the results.
Bu also found that oldest children in the survey are seven percent more ambitious than children born later, based on responses to a question about educational plans at age 13. The gender gap is also bigger for ambition: Firstborn girls are 13 percent more likely to aspire to higher education than firstborn boys. The results held up regardless of parents’ education and professional achievement levels.
As a firstborn girl myself, I can’t say I’m surprised. But before we chosen ones let this study go to our heads, Bu points out that the effect is probably more due to nurture than nature.
"There are several possible explanations for the higher attainment and ambition of the eldest," Bu told The Guardian. "It could be that the parents simply devote more time and energy to them—it could be that they are actually more intelligent. For me, I tend to lean towards the theory that parental investment is possibly at work here."
In characteristic fashion, she added, "I'm the firstborn, of course. That is why I'm doing a PhD."
Firstborns may be successful because they suck up a greater share of their parents’ resources. Oldest children naturally get a period of exclusive attention simply by being first. And the special treatment continues even after other children arrive: Think about all the perks firstborns get to make sure they don’t feel upstaged by the new baby (I got a trip to Disney World when my sisters were born).
The extra attention may translate into greater intelligence. In a 2007 study, for example, firstborns scored about three points higher on IQ tests than their younger siblings. If the firstborn had died in childhood, however, the second born took on the mantle and scored as high as the true firstborns—suggesting that the difference in intelligence isn’t necessarily innate.
It’s not all bad news for younger siblings. Birth order expert and visiting professor at the University of California, Berkeley, Frank Sulloway has proposed that siblings compete for parental favor and investment by adopting different roles within the family. If the firstborn is the brain,the second child may be the sporty one or the actress. And in Bu’s study, the longer the spacing between kids in a family, the smaller the gap in siblings’ educational achievement.