Table 4.
Comparison of ACE models in both birth cohorts
| Compare cohorts | -2 LL | Df | Versus | Χ2 | Δ df | p | |
|---|---|---|---|---|---|---|---|
| 1 | Full ACE | 5676.915 | 4990 | ||||
| 2 | Constrain Rcdos at 1 | 5677.127 | 4992 | 1 | 0.212 | 2 | 0.8994 |
| 3 | EQ ACE for men over cohorts | 5677.825 | 4995 | 2 | 0.698 | 3 | 0.8737 |
| 4 | EQ ACE for women over cohorts | 5677.692 | 4995 | 2 | 0.565 | 3 | 0.9044 |
| 5 | EQ ACE for both sexes over cohorts | 5678.229 | 4998 | 2 | 1.102 | 6 | 0.9814 |
| 6 | No sex differences in contributions of A,C,E | 5688.117 | 5001 | 5 | 9.888 | 3 | 0.0195 |
| 7 | Drop A | 5718.180 | 5002 | 6 | 39.951 | 1 | < 0.0001 |
| 8 | Drop C | 5695.529 | 5002 | 6 | 7,412 | 1 | 0.0064 |
Full ACE: the influence of A, C and E factors is estimated separately for men and women and for both cohorts. The shared environmental correlation (Rc) in DZ twins of opposite sex (DOS) is estimated as a free parameter. Model 2: test for qualitative sex differences (Rcdos is fixed at 1). Model 3: ACE in cohort 1993-1995 is equalized to ACE in cohort 2009-2010 for men. Model 4: ACE in cohort 1993-1995 is equalized to ACE in cohort 2009-2010 for women. Model 5: ACE in cohort 1993-1995 is equalized to ACE in cohort 2009-2010 for men and women simultaneously. Model 6: ACE for men is equalized to ACE for women. Model 7: Additive genetics effects (A) are dropped. Model 8: Shared environmental influences (C) are dropped