@article{Zajonc1976,
author = {Zajonc, R.B.},
title= {Family configuration and intelligence: Variations in scholastic aptitude scores parallel trends in family size and the spacing of children},
year = {1976},
doi = {10.1126/science.192.4236.227},
volume = {192},
number = {4236},
pages = {227--236},
}