Key points are not available for this paper at this time.
Abstract This study investigated the historical trend in resemblance between first‐degree relatives for age at death. Data from genealogies of six New England families (N = 13,656) were divided into nine 25 year birth cohorts, 1650–1874, to test the hypothesis that familial influence on human longevity has changed during the past 300 years. Heritability (h 2 ) for longevity demonstrated no historical trend, whether calculated by regression of offspring's longevity on paternal, maternal, or mid‐parental longevity or by intraclass correlations (t) among sibships. Ninety‐five percent confidence intervals (C.I.) for h 2 (additive genetic variance) were in the range 0.10–0.33 for parent–offspring regressions and 0.16–0.22 based on mean of sibship regressed on mean of parents. Based on sibship t, the 95% C.I. for the upper limit to h 2 (which includes variance contributions caused by dominance interactions and common developmental environment as well as additive genetic effects) was 0.33–0.41. In this socially elite sample, the statistical contribution of first‐degree relatives to age at death has varied within a historically consistent range over the past 300 years, directly implying a persistent genetic influence on longevity. The magnitude of this influence with respect to additive genetic variance, about 10–30%, may overestimate h 2 because of the elite nature of the sample. Nevertheless, these results support a genetic component to lifespan even though the majority of variation in human longevity is not explained by genetic factors.
Péter J. Mayer (Tue,) studied this question.