Older siblings, prepare for some research-backed bragging rights. A rather interesting study out of the German University of Leipzig has concluded that older children may often be ‘smarter’ (based around test scores that measured verbal, reading, math, and comprehension abilities) than their younger siblings.
According to the study findings published back in 2017 via The University of Edinburgh, each younger child appeared to have an IQ drop of 1.5 points from their older sibling – though this deviation didn’t necessarily apply to families where there were only two children, as the older siblings in such cases only had a 60% chance of being ‘more intelligent’.
So, naturally, we ask the question: what leads to this potential intelligence difference? Why do, according to this research, older children have a theoretical advantage when it comes to intelligence?
Firstborn Siblings May Receive More Attention, Teach Younger Siblings
The researchers behind the study report that one large contributing factor may be the higher social status given to the older child, in addition to the idea that the older child must also become a ‘teacher’ for the younger sibling throughout childhood.
It is also believed that because the older child may be the sole focus of the parents’ attention for several months to several years, the older child could receive a cognitive boost from the increased time and attention.
Dr. Julia Rohrer, the co-author of the study, explained the phenomenon:
“While the firstborn gets full parental attention, at least for some months or years, late-borns will have to share from the beginning. Another possible factor is described by the tutoring hypothesis: A firstborn can “tutor” their younger siblings, explaining to them how the world works and so on.”
“Teaching other people has high cognitive demands – the children need to recall their own knowledge, structure it and think of a good way to explain it to younger siblings, which could provide a boost to intelligence for some firstborns.”
The study examined 20,000 individuals from the United Kingdom, United States and Germany, and found that birth order does little to affect personality as many believe, but that it may have a clear affect on intelligence.
But Younger Siblings More Likely to Be ‘Healthier’, Resistant to Autoimmune Disorders
The study isn’t all bad news for younger siblings, though. It was also found that younger siblings were more likely to be ‘healthier’ than their older siblings, and even less likely to develop autoimmune disorders. The researchers theorized that this may have something to do with changes in the womb, or the fact that younger children are exposed to more diseases earlier thanks to their older sibling.