Earlier studies in Scandinavian and other countries have already found that firstborns are more likely to be ambitious than younger siblings, though that research did not consider the gender of the firstborns.
The new research followed 1,500 sibling groups (3,532 children) through the British Household Panel Study and a subsequent study. After controlling for parent education and professional status, the researchers said firstborns were 7 percent more likely to continue to get an education, compared to younger brothers and sisters.
The research also noted that having more time between the births of siblings increases the likelihood of higher educational attainment.
Slate's Katy Waldman wrote: "On the other hand, the researchers write, 'We see no evidence that the sex of one’s siblings has any effect on educational aspiration or outcomes. Nor do we find a strong relationship between sibship size and either educational aspiration or attainment.' (So you can’t blame your grades on how many siblings you have or what gender they are.) What does seem meaningful is the time spacing between children: Eldest kids separated from their brothers and sisters by a significant age gap — four or more years — are likelier, at 13, to express an interest in higher education, and they go on to pursue more advanced degrees."
“Educational disparities exist not only between families but also within families. It is interesting that we observe a distinct firstborn advantage in education even though parents in modern society are more likely to be egalitarian in treating their children,” Bu said in a written statement accompanying the study.
She told The Guardian that it's possible firstborns get more parental attention and energy, a theory she places ahead of the idea that firstborns are simply smarter.