Matched (blue) and mismatched (green) father–son pairs by year of birth for son. We used exact logistic regression to calculate the odds of nonpaternity (yes, no) with year of birth (years) as the predictor variable. (A) Dogon religion only (exact odds ratio = 1.00, 95% confidence limits = 0.99–1.02, P = 0.677). (B) All religions (exact odds ratio = 1.01, 95% confidence limits = 1.00–1.02, P = 0.064).