What do Hillary Clinton, Beyonce, and Sheryl Sandberg all have in common?
Each is a firstborn daughter.
That pattern of ambition and birth order is validated in a new British study, which found that firstborn daughters are the most likely to achieve academic success.
Feifei Bu at the University of Essex investigated 3,552 people organised into 1,503 sibling groups from the British Household Panel Survey.
The most surprising result were the differences between gender. She found that firstborn daughters were 13% more ambitious than firstborn sons, and that girls were 4% more likely to have greater education than their siblings.
But birth order had broader impacts. Firstborn kids were 7% more likely to aspire to continue their education than younger siblings, while they also had a 16% higher probability of completing higher education than younger siblings.
Still, we need to be careful about the applications of these results. When we reached out to her, Bu warned that we shouldn’t over-generalize to overall success and should also keep in mind that this is a U.K.-specific study (although others have investigated other countries).
“My results show that this educational advantage can be partially explained by the fact that they tend to have higher aspirations than their later-born siblings,” Bu wrote to us in an email.
“My results confirm that adolescents’ educational aspiration has a significant impact on their educational attainment in later life.”
While Bu’s study doesn’t go into the mechanism as to while the firstborn kids have the highest aspiration and attainment, other theories have attempted to explain why.
Stanford psychologist R.B. Zajonc provided one explanation back in the 1970s. In what became known as the “confluence theory,” he said that a child’s intellectual development is shaped by the intellectual environment she finds herself in.
Consider, then, what happens when more kids come along after the first: the average intellectual age goes down.
In Bu’s description, the “intellectual level in the family will be diluted by newborns.”
In 2002, Columbia University psychologist Ralph Hertwig supplied an alternative case called the “equity heuristic,” which maintains that parents try to invest the same amount of attention to each kid. But that leads to a surprising result: given that firstborns have a period of undivided attention, they get the most investment.
A third explanation comes from University of California psychologist Frank Sulloway. He applies an evolutionary lens, arguing that human children — like all offspring — compete with each sibling for their parents’ scarce attention.
So each child tries to be exceptional in his or her own way, be it through academic, athletic, or creative success. Again, the firstborn is able to seize the initiative.
“The advantage of being the firstborn is that one is able to choose one’s ‘niche’ first,” Bu writes, “without reference to the roles already adopted by other siblings.”
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