Science has found that the order you were born — whether the first, middle or last child — does make a difference to your intelligence and personality.
A massive study of 377,000 high school students found that those children born first in a family do have higher IQs — by about one point — than their later born siblings.
But this difference is so small that it has no practical meaning.
And there are consistent differences in personality traits. First borns tend to be more extroverted, agreeable and conscientious and have less anxiety than brothers or sisters who came later.
Again, the differences are described as “infinitesimally small”.
“You’re not going to be able to sit two people down next to each other and see the differences between them,” says University of Illinois psychology professor Brent Roberts. “It’s not noticeable by anybody.”
The study compensated for potentially confounding factors such as a family’s economic status, the number of children and the relative age of the siblings.
Wealthier families tend to have fewer children and so have a higher proportion of first-borns who also have access to more resources which might influence IQ and personality.
“The message of this study is that birth order probably should not influence your parenting, because it’s not meaningfully related to your kid’s personality or IQ,” says postdoctoral researcher Rodica Damian.
The study is reported in the Journal of Research in Personality.
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