Table 5.
Heritability, common environment, and residual error estimates (Est), standard errors (SEs), and lower and upper 95% confidence limits (LCL, UCL) by phenotype, zygosity, age, and affectedness (Aff) criteria.
| Outcome | Aff criterion | Age |
h
2 heritability |
c
2 common environment |
e
2 residual error |
|||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Est | SE | LCL | UCL | Est | SE | LCL | UCL | Est | SE | LCL | UCL | |||
| PPVT-III Vocabulary | −1.00 SD | 4 | .64 | .24 | .03 | 1.00 | .07 | .20 | .00 | .39 | .29 | .08 | .08 | .41 |
| 6 | .86 | .37 | .00 | 1.00 | .00 | .33 | .00 | .43 | .36 | .10 | .01 | .41 | ||
| −1.25 SD | 4 | .16 | .31 | .00 | .66 | .43 | .23 | .00 | .81 | .41 | .12 | .10 | .61 | |
| 6 | .37 | .37 | .00 | .98 | .39 | .31 | .00 | .90 | .24 | .11 | .00 | .43 | ||
| −1.50 SD | 4 | −.15 | .43 | .00 | .56 | .61 | .30 | .00 | 1.00 | .53 | .18 | .08 | .82 | |
| 6 | .37 | .41 | .00 | 1.00 | .48 | .36 | .00 | 1.00 | .15 | .10 | .00 | .32 | ||
| TOLD-P:3 Spoken Language | −1.00 SD | 4 | .36 | .19 | .00 | .67 | .37 | .15 | .00 | .61 | .28 | .07 | .10 | .39 |
| 6 | .65 | .19 | .16 | .96 | .13 | .16 | .00 | .39 | .22 | .06 | .06 | .32 | ||
| −1.25 SD | 4 | .23 | .24 | .00 | .62 | .40 | .18 | .00 | .70 | .37 | .09 | .13 | .52 | |
| 6 | .83 | .19 | .34 | 1.00 | .05 | .17 | .00 | .33 | .13 | .05 | .01 | .20 | ||
| −1.50 SD | 4 | .59 | .34 | .00 | 1.00 | .13 | .28 | .00 | .58 | .28 | .11 | .00 | .47 | |
| 6 | .73 | .24 | .12 | 1.00 | .11 | .21 | .00 | .46 | .16 | .06 | .00 | .27 | ||
| TOLD-P:3 Semantics | −1.00 SD | 4 | .28 | .24 | .00 | .67 | .27 | .18 | .00 | .56 | .45 | .09 | .21 | .60 |
| 6 | .52 | .25 | .00 | .93 | .09 | .19 | .00 | .40 | .39 | .09 | .15 | .54 | ||
| −1.25 SD | 4 | .30 | .34 | .00 | .85 | .11 | .25 | .00 | .52 | .59 | .13 | .25 | .81 | |
| 6 | .79 | .26 | .12 | 1.00 | .00 | .22 | .00 | .29 | .34 | .08 | .07 | .41 | ||
| −1.50 SD | 4 | .26 | .41 | .00 | .94 | .21 | .30 | .00 | .70 | .53 | .17 | .10 | .80 | |
| 6 | .87 | .28 | .16 | 1.00 | .00 | .24 | .00 | .29 | .33 | .08 | .02 | .37 | ||
| TOLD-P:3 Syntax | −1.00 SD | 4 | .69 | .19 | .21 | .99 | .11 | .16 | .00 | .37 | .20 | .06 | .05 | .30 |
| 6 | .63 | .19 | .15 | .94 | .17 | .16 | .00 | .43 | .20 | .06 | .05 | .30 | ||
| −1.25 SD | 4 | .33 | .27 | .00 | .77 | .28 | .21 | .00 | .62 | .39 | .10 | .13 | .55 | |
| 6 | .88 | .22 | .31 | 1.00 | .00 | .20 | .00 | .27 | .23 | .06 | .03 | .27 | ||
| −1.50 SD | 4 | .21 | .32 | .00 | .74 | .36 | .25 | .00 | .77 | .43 | .12 | .12 | .63 | |
| 6 | .90 | .22 | .34 | 1.00 | .00 | .20 | .00 | .32 | .13 | .05 | .00 | .19 | ||
| GFTA-2 Speech | −1.00 SD | 4 | .24 | .28 | .00 | .70 | .60 | .24 | .00 | .99 | .16 | .09 | .00 | .31 |
| 6 | 1.52 | .50 | .25 | 1.00 | .00 | .47 | .00 | .10 | .84 | .09 | .00 | .30 | ||
| −1.25 SD | 4 | .28 | .24 | .00 | .67 | .66 | .21 | .10 | 1.00 | .07 | .06 | .00 | .17 | |
| 6 | .89 | .52 | .00 | 1.00 | .03 | .51 | .00 | .86 | .08 | .07 | .00 | .20 | ||
| −1.50 SD | 4 | .14 | .25 | .00 | .56 | .76 | .21 | .22 | 1.00 | .10 | .08 | .00 | .23 | |
| 6 | .69 | .51 | .00 | 1.00 | .22 | .49 | .00 | 1.00 | .10 | .08 | .00 | .23 | ||
| MLU | −1.00 SD | 4 | .83 | .27 | .14 | 1.00 | .00 | .21 | .00 | .15 | .56 | .09 | .12 | .52 |
| 6 | .74 | .29 | .00 | 1.00 | .00 | .23 | .00 | .25 | .51 | .10 | .12 | .55 | ||
| −1.25 SD | 4 | .64 | .29 | .00 | 1.00 | .02 | .23 | .00 | .40 | .34 | .10 | .08 | .51 | |
| 6 | .38 | .40 | .00 | 1.00 | .00 | .30 | .00 | .47 | .67 | .15 | .25 | .90 | ||
| −1.50 SD | 4 | 1.09 | .30 | .32 | 1.00 | .00 | .27 | .00 | .18 | .44 | .08 | .00 | .30 | |
| 6 | ||||||||||||||
| TEGI Composite | −1.00 SD | 4 | .48 | .16 | .06 | .75 | .34 | .13 | .00 | .56 | .18 | .05 | .04 | .26 |
| 6 | .71 | .20 | .19 | 1.00 | .08 | .17 | .00 | .36 | .22 | .06 | .06 | .32 | ||
| −1.25 SD | 4 | .42 | .17 | .00 | .70 | .39 | .14 | .04 | .62 | .19 | .06 | .05 | .29 | |
| 6 | .91 | .19 | .43 | 1.00 | .00 | .17 | .00 | .25 | .15 | .04 | .01 | .19 | ||
| −1.50 SD | 4 | .43 | .17 | .00 | .71 | .40 | .14 | .04 | .63 | .17 | .06 | .03 | .26 | |
| 6 | .86 | .19 | .37 | 1.00 | .04 | .18 | .00 | .33 | .10 | .04 | .00 | .17 | ||
| TEGI Screener | −1.00 SD | 4 | .54 | .16 | .13 | .80 | .31 | .14 | .00 | .54 | .15 | .05 | .03 | .23 |
| 6 | .29 | .24 | .00 | .69 | .36 | .19 | .00 | .66 | .36 | .09 | .13 | .50 | ||
| −1.25 SD | 4 | .51 | .16 | .10 | .77 | .36 | .14 | .01 | .58 | .14 | .05 | .02 | .21 | |
| 6 | .49 | .23 | .00 | .86 | .27 | .19 | .00 | .58 | .25 | .08 | .06 | .37 | ||
| −1.50 SD | 4 | .50 | .15 | .11 | .75 | .39 | .13 | .04 | .61 | .11 | .04 | .01 | .18 | |
| 6 | .52 | .23 | .00 | .90 | .28 | .20 | .00 | .60 | .20 | .07 | .02 | .32 | ||
| CMMS Nonverbal IQ | −1.00 SD | 4 | .01 | .39 | .00 | .65 | .31 | .27 | .00 | .76 | .68 | .16 | .27 | .95 |
| 6 | 1.39 | .51 | .07 | 1.00 | .00 | .48 | .00 | .22 | .76 | .10 | .00 | .35 | ||
| −1.25 SD | 4 | −.81 | .60 | .00 | .18 | .89 | .38 | .00 | 1.00 | .92 | .27 | .23 | 1.00 | |
| 6 | .37 | .26 | .00 | .80 | .06 | .21 | .00 | .41 | .57 | .09 | .35 | .72 | ||
| −1.50 SD | 4 | .18 | .74 | .00 | 1.00 | .35 | .57 | .00 | 1.00 | .47 | .27 | .00 | .92 | |
| 6 | .20 | .17 | .00 | .48 | .41 | .13 | .07 | .63 | .39 | .06 | .23 | .50 | ||
Note. Negative heritability estimates occurred when the intraclass correlation for dizygotic twins was greater than the intraclass correlation for monozygotic twins, and heritability estimates greater than 1 occurred in models where the intraclass correlation for monozygotic twins was .5 greater than the intraclass correlation for dizygotic twins. LCLs and UCLs were truncated at 0 and 1, respectively; c 2 estimates ≤ 0 were converted to 0. Blank rows indicate that the model did not estimate. PPVT-III = Peabody Picture Vocabulary Test–III; TOLD-P:3 = Test of Language Development–Primary: Third Edition; GFTA-2 = Goldman-Fristoe Test of Articulation–Second Edition; MLU = mean length of utterance as calculated by SALT software; TEGI = Rice–Wexler Test of Early Grammatical Impairment; CMMS = Columbia Mental Maturity Scale.