Down's syndrome and human behaviour

Abstract

GERMAN1 has proposed that Down's syndrome may be the result of delayed fertilization consequent to sporadic or decreased frequency of coitus. It has also been suggested1 that this hypothesis could be tested by comparing the incidence of this syndrome in similar groups differing only in the frequency of coitus and also by studying the incidence of the syndrome in the offspring of recently married older mothers and of unmarried mothers. © 1968 Nature Publishing Group.