The Firstborn-Only Child Edge

by Susan Newman, Ph.D.

Twelve men have walked on the moon. All of them were firstborns or only children. In terms of level of education, aspirations and achievement, firstborns and only children excel. What gives firstborns and only children this distinct advantage?

Accepting that for a period of time firstborns are only children, the advantage can be partially explained by the Dilution Theory. In families, the finite resources parents have means that any given sibling will be given less time...