This work is licensed under a Table 4.
Unconditional growth model parameters.
| Parameter | Missing Do Total R2 = .099 |
Ungrammatical Lex Total R2 = .086 |
Ungrammatical Do + Lex Total R2 = .134 |
Double Tense Total R2 = .138 |
||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Est | SE | 95% CI |
p < | Est | SE | 95% CI |
p < | Est | SE | 95% CI |
p < | Est | SE | 95% CI |
p < | |||||
| LL | UL | LL | UL | LL | UL | LL | UL | |||||||||||||
| Fixed effects | ||||||||||||||||||||
| Int (age 10 years) | .77 | .01 | .75 | .78 | .001 | .78 | .01 | .76 | .80 | .001 | .83 | .01 | .81 | .85 | .001 | .68 | .01 | .65 | .70 | .001 |
| Linear age slope | .16 | .02 | .14 | .19 | .001 | .14 | .02 | .11 | .17 | .001 | .20 | .02 | .16 | .23 | .001 | .27 | .02 | .24 | .30 | .001 |
| Quad age slope | −.28 | .03 | −.34 | −.22 | .001 | −.34 | .03 | −.41 | −.28 | .001 | −.36 | .03 | −.42 | −.30 | .001 | −.19 | .03 | −.25 | −.13 | .001 |
| Linear age cohort | .09 | .02 | .04 | .13 | .001 | .07 | .02 | .02 | .11 | .004 | .07 | .02 | .03 | .12 | .001 | −.03 | .02 | −.08 | .02 | .194 |
| Quad age cohort | .31 | .07 | .17 | .45 | .001 | |||||||||||||||
| Random effects: Variance components | ||||||||||||||||||||
| L1 residual | .04 | .00 | .04 | .04 | .001 | .03 | .00 | .03 | .04 | .001 | .03 | .00 | .03 | .03 | .001 | .04 | .00 | .03 | .04 | .001 |
| L2 int | .02 | .00 | .01 | .02 | .001 | .01 | .00 | .01 | .02 | .001 | .01 | .00 | .01 | .02 | .001 | .01 | .00 | .01 | .01 | .001 |
| L2 linear | .01 | .01 | .01 | .03 | .001 | .02 | .01 | .01 | .04 | .001 | .03 | .01 | .02 | .04 | .001 | .02 | .01 | .01 | .03 | .001 |
| L2 quad | .03 | .03 | .01 | .37 | .101 | .11 | .03 | .07 | .21 | .001 | .06 | .03 | .03 | .19 | .018 | |||||
| L2 int–linear | .01 | .00 | .00 | .01 | .001 | .00 | .00 | .00 | .01 | .793 | .00 | .00 | −.01 | .00 | .403 | .01 | .00 | .01 | .01 | .001 |
| L2 int–quad | −.02 | .01 | −.03 | −.01 | .001 | −.03 | .01 | −.04 | −.02 | .001 | −.02 | .01 | −.03 | −.01 | .001 | |||||
| L2 linear–quad | −.02 | .01 | −.03 | .00 | .018 | .00 | .01 | −.02 | .01 | .797 | .01 | .01 | .00 | .03 | .083 | |||||
| L3 int | .00 | .00 | .00 | .01 | .001 | .01 | .00 | .00 | .01 | .001 | .01 | .00 | .01 | .01 | .001 | .01 | .00 | .00 | .01 | .001 |
Note. The time-varying predictor of age and the effects of age cohort were log-transformed. The intercept parameter is time-varying log-age, centered at log-age 10 years, and represents the average A′ outcome at 10 years of age. The estimates for linear and quadratic effects of age cohort represent the cross-sectional effects of children's exact age at study entry, centered at log-age 8 years, on the intercept. Bold values indicate p < .01. Covariances indicated with dash (–). Blank cells indicate effects not included in a particular model due to nonsignificance. Est = estimate; SE = standard error; CI = confidence interval; LL = lower limit; UL = upper limit; Int = intercept; Quad = quadratic; L1 residual = variance over time and within persons; L2 = Level 2: variance across persons within families; L3 = Level 3: variance within families.