Variance Parameters
Cohort Size
Falconer's Formula
h² = 2 × (r_MZT - r_DZT)
2 × (0.70 - 0.41) = 0.58
Theoretical Correlations
r_MZT = h² + c²
r_DZT = 0.5×h² + c²
r_MZA = h²
r_DZA = 0.5×h²
Variance Decomposition
Empirical h²
0.58
Empirical c²
0.12
Empirical e²
0.30
Cross-Twin Correlations (r)
r(MZT) Reared Together
0.70
r(DZT) Reared Together
0.41
r(MZA) Reared Apart
0.58
r(DZA) Reared Apart
0.12
Monozygotic Reared Together (MZT)
r = 0.70
Dizygotic Reared Together (DZT)
r = 0.41
Monozygotic Reared Apart (MZA - Jim Twins)
r = 0.58
Dizygotic Reared Apart (DZA)
r = 0.12