Fig. 4

Proportion of variation in DNAm age measured by the epigenetic clock across the lifespan explained by genetic and environmental factors. Lines are the predicted proportions of variation explained by genetic and environmental factors from the variance components modeling, and shadows are the corresponding 95% confidence intervals. A: additive genetic factors; C: shared environmental factors; E: individual-specific environmental factors; MZ monozygotic twin, DZ Dizygotic twin. Model details—AE model: variation was assumed to be caused by only A and E, and the effects of A are constant across the lifespan; cohabitation-dependent AE model: variation was assumed to be caused by only A and E, and the effects of A depend on cohabitation; cohabitation-dependent ACE model: variation was assumed to be caused by A, C and E, and the effects of A and C both depend on cohabitation; cohabitation-dependent CE model: variation was assumed to be caused by only C and E, and the effects of C depend on cohabitation