Child mortality and cohort lifespan: a test of diminished entelechy

Background The literature implies a 'diminished entelechy' hypothesis in which birth cohorts subjected to relatively many or relatively virulent environmental insults early in life do not realize their otherwise expected lifespan. No direct test of this hypothesis appears in literature. Methods We test the hypothesis directly by measuring the association between mortality in the first 5 years and life expectancy at age 5 for male and female cohorts born in Sweden (1751-1912), Denmark (1835-1913), and England and Wales (1841-1912). The methods control for trends, seasonal cycles, and other forms of autocorrelation that could induce spurious associations. Results Our results support the hypothesis in that life expectancy at age 5 fell below the values expected from history in cohorts in which child mortality before age 5 increased over its expected value. We find no evidence for culling effects in which a cohort remaining after suffering relatively many environmental insults may be smaller but hardier than expected. Conclusions These findings converge with individual-level studies and suggest that suffering relatively virulent or many environmental insults during childhood reduces the subsequent lifespan of birth cohorts.