First borns tend to be smarter than their siblings but it’s got nothing to do with genetics.

If you happen to be a first born child, you can give up the game. Us younger siblings have put enough of your rubbish about being smarter because well, you just think you’re smarter. The fact is, just like a lot of things, you do better because mum and dad gave you more. More time that is.

Historically the assumption has been that first born children tend to be smarter than their younger siblings due to biological reasons but updated research presented recently at the Royal Economic Society’s annual conference suggests that this is actually incorrect.

While true that first born children may perform better academically than their siblings, the reason has more to do with the way they were raised, and their parents level of engagement in their education than anything genetically programmed.

For all the stressed-out, time-poor mums out there.
First born children perform better in school than younger siblings (istock)

According to this study, parents are far more likely to be involved in monitoring and assessing homework and are more likely to spent quality time with their children. Us subsequent kids tend to miss out on the interaction our first born siblings enjoyed, often simply because of the increased pressure on parents and their increased workload. Which, you know, makes sense.

"Researchers had not looked at health but had suggested firstborns were doing better in school because of biology. We have proven for the first time it isn't to do with biology. Therefore, if it's not due to health, then it must be down to something that happens after birth. For instance, children's interactions with their parents and how much quality time they spend with their children.” says Ramona Molitor, one of the researchers.

The study analysed over one million children between 1981 and 2010. It found that because of the support first born children received from their parents in relation to their education, their academic levels were approximately one educational grade higher than their siblings by the middle of high school.

The study analysed over one million children between 1981 and 2010 (istock)

Interestingly though the study also found that first born children tended to suffer from poorer health than subsequent siblings. Contrary to what was previously thought, first borns are more likely to be less healthy at birth and suffer from birth related complications and prematurity.  Researchers have suggested that one reason for this could be that mothers were more likely to be drinking and smoking during their first pregnancies.


According to the findings first born children were five per cent below the normal range, one per cent shorter than their siblings and had smaller heads. Subsequent siblings were also found to be far less likely (55 to 73 per cent) to be premature.

Researcher Ramona Molitor and Anne Ardija Brenoe say that when taking siblings health into consideration, the educational gap may actually be increased. Researchers told the Telegraph “The firstborns’ health disadvantage stands in stark contrast to their educational achievement later in life. Firstborns perform better in school than their younger siblings – and the achievement gap increases when accounting for differences in health at birth.”


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