Table 4.
Model fitting results of multivariate genetic analyses for Attention Problems (AP) at age 5 and at age 7, Comprehension (COM), Mathematics (MAT), and Spelling (SPEL), across grades
| −2 LL | X2 | df | p | r | |
|---|---|---|---|---|---|
| COM | |||||
| ACE | 15406.247 | ||||
| CE | 15350.153 | 56.094 | 10 | 0.000 | |
| AE | 15408.848 | 2.601 | 10 | 0.989 | |
| 2 factor model | |||||
| r free | 15418.166 | 11.919 | 13 | 0.534 | −0.28 |
| r = 0 | 15427.412 | 21.165 | 14 | 0.097 | |
| r = 1 | 15441.789 | 35.542 | 14 | 0.000 | |
| MAT | |||||
| ACE | 18116.007 | ||||
| CE | 18176.047 | 60.040 | 15 | 0.000 | |
| AE | 18128.208 | 12.201 | 15 | 0.664 | |
| 2 factor model | |||||
| r free | 18141.068 | 25.061 | 22 | 0.294 | −0.40 |
| r = 0 | 18161.127 | 45.120 | 23 | 0.003 | |
| r = 1 | 18182.685 | 66.676 | 23 | 0.000 | |
| SPEL | |||||
| ACE | 17509.073 | ||||
| CE | 17454.409 | 54.664 | 15 | 0.000 | |
| AE | 17516.467 | 7.394 | 15 | 0.946 | |
| 2 factor model | |||||
| r free | 17530.806 | 21.733 | 22 | 0.536 | −0.28 |
| r = 0 | 17541.518 | 32.445 | 23 | 0.091 | |
| r = 1 | 17569.775 | 60.702 | 23 | 0.000 | |
Note: Constrained models were compared to Cholesky model; A = additive genetic factors, C = common environmental factors, E = unique environmental factors; r = correlation between the latent genetic factors