Survival of nieces and nephews of schizophrenic patients.
Evidence was found against the hypothesis that heterozygous carriers of a schizophrenic gene have a reproductive advantage through enhanced fertility. In consequence an investigation was made of the possibility that an advantage is gained through diminished early mortality among the off-spring of carriers. The results were equivocal. While an observed deficit of infant deaths was attributable to under-reporting, the possibility of a true advantage could not be ruled out, because of the statistical unreliability of the findings in a sample of the size available. A plea is made for a collaborative effort to settle the issue.