If you’re the oldest sibling in your family, there’s good news.
You finally get to tell your sibling “I told you so,” because science says you’re probably smarter.
A new study found that the oldest child of every family tends to be the smartest. Every younger sibling tends to be little less smart than the previous.
The difference is small—about 1.5 IQ points drop from sibling to sibling—but it’s a clear drop.
And it’s not just in actual intelligence. Younger siblings perceive themselves as less smart than their siblings, too.
The research, done by the Leipzig University, looked at the results of three national studies, which involved 20,000 people. It was one on families with two to four children, as families with more children were too rare and therefore unable to have meaningful input.
The drop in IQ was obvious, as was the perception of their own intelligence.
This was the only significant change found though. No changes in personality were perceived.
The answer, say researchers, isn’t in their genetics, but rather in their upbringing.
Eldest siblings get full attention from their parents, at least for a while. Younger siblings don’t have the benefit of being the only child, even for a few months.
Another theory is that firstborns tutor their younger siblings, which in turn makes them smarter. Teaching puts cognitive demands on the brain in a way that learning does not.
Whatever the cause, the link was there. But younger siblings shouldn't give up hope just yet.
Of course, the study showed about a six out of ten chance that the eldest will be the smartest, which leaves plenty of room for younger siblings to step it up.
