Table 3.
Unstandardized Parameter Estimates from Longitudinal Models of Mental Ability at 2 Years and Mathematics at 4 Years
| Parameter | Mental Ability (“2y” subscript)
|
Mental Ability→Mathematics (“b” subscript)
|
Mathematics. Mental Ability (“4y” subscript)
|
|||
|---|---|---|---|---|---|---|
| Estimate | 95% CI | Estimate | 95% CI | Estimate | 95% CI | |
| a | .449 | (.329, .569) | .046 | (−.121, .213) | .380 | (.258, .502) |
| a′ | .137 | (.055, .219) | .073 | (−.043, .189) | .109 | (.019, .199) |
| c | .659 | (.581, .737) | .297 | (.189, .405) | .594 | (.514, .674) |
| c′ | −.038 | (−.114, .038) | −.028 | (−.128, .072) | −.030 | (−.108, .048) |
| e | .454 | (.411, .497) | .088 | (.031, .145) | .389 | (.348, .430) |
| e′ | −.028 | (−.061, .005) | −.005 | (−.050, .040) | −.003 | (−.040, .034) |
| s | .335 | (.270, .400) | .480 | (.417, .543) | ||
| LL | −2806.33 | |||||
| Parameters | 22 | |||||
Note. Mental Ability refers to the total A, C, and E effects on mental ability scores at 2 years. Mental Ability→Mathematics refers to the regression of Mathematics at 4 years on the A, C, and E components of mental ability at 2 years. Mathematics. Mental Ability refers to the unique A, C, and E effects on Mathematics at 4 years. The a, c, and e parameters reflect the main effects of genes, shared environment, and nonshared environment, respectively. The corresponding interaction terms (a′,c′,e′) reflect the interaction of each biometric component with SES. The parameter s reflects the main effect of SES. Bold parameters are significant at p < .05. LL is the value of the loglikelihood function for each model, and Parameters is the number of model parameters that were estimated.