Previous research has shown that performance on psychometric intelligence tests decline slightly from first-borns to later-borns (scientifically-based evidence of our awesomeness).
I’m first-born in our family. So’s my husband. So are a lot of my friends. Because it’s important to keep the Circle of Awesomeness.
Before you second-borns (and above) get all upset – please kindly remember that in exchange for this intelligence we bear the brunt of all parental discipline. That time you got a B+ and didn’t get beaten? You can thank us later.
This study with >20,000 subjects found (once again) that first-borns have higher intelligence. Interestingly they also found a significant decline on self-reported intellect with increasing birth-order (independent of objectively measured intelligence). At least they have insight then. 😉
No relationship was found between birth-order and personality traits such as extraversion, emotional stability, agreeableness, conscientiousness, and imagination.
Rohrer JM, Egloff B, Schmukle SC. Examining the effects of birth order on personality. Proc Natl Acad Sci U S A. 2015 Oct 19. pii: 201506451.