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Table 4 Comparison of ACE models in both birth cohorts

From: Interplay between heritability of smoking and environmental conditions? A comparison of two 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

  1. 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