Table 1.
Participant Characteristics for the Full-Sample DS, FXS, and TD Groups
| Characteristic | Group
|
p | d | ||
|---|---|---|---|---|---|
| DS (n = 24) | FXS (n = 12) | TD (n = 21) | |||
| Chronological Age (years) | < 0.001 | DS/FXS: 0.68 DS/TD: 5.29 FXS/TD: 5.31 |
|||
| Mean | 16.90 | 14.95 | 4.82 | ||
| SD | 3.14 | 2.59 | 0.76 | ||
| Min-Max | 12.08–23.37 | 11.38–19.74 | 3.61–6.66 | ||
| Nonverbal Mental Age (years)a | 0.29 | DS/FXS: 0.54 DS/TD: 0.06 FXS/TD: −0.44 |
|||
| Mean | 4.94 | 4.38 | 4.87 | ||
| SD | 1.04 | 1.03 | 1.21 | ||
| Min-Max | 3.31–7.06 | 2.86–7.11 | 3.42–7.84 | ||
| Nonverbal IQa | < 0.001 | DS/FXS: 0.34 DS/TD: −6.81 FXS/TD: −5.37 |
|||
| Mean | 41.71 | 39.50 | 98.00 | ||
| SD | 6.87 | 6.05 | 9.45 | ||
| Min-Max | 36–57 | 36–56 | 84–115 | ||
| Number of C-unitsb | 0.68 | DS/FXS: 0.12 DS/TD: −0.23 FXS/TD: −0.34 |
|||
| Mean | 67.42 | 65.67 | 71.43 | ||
| SD | 14.44 | 13.83 | 19.58 | ||
| Min-Max | 50–96 | 51–95 | 50–121 | ||
| Mean Length of Utterance (morphemes)b | 0.51 | DS/FXS: 0.36 DS/TD: 0.05 FXS/TD: −0.44 |
|||
| Mean | 6.53 | 5.97 | 6.45 | ||
| SD | 1.95 | 1.01 | 1.15 | ||
| Min-Max | 3.40–11.20 | 4.43–8.10 | 3.86–8.06 | ||
| Race | 0.08 | Cramer’s V = 0.30 | |||
| White:Other | 24:0 | 11:1 | 17:4 | ||
| Maternal Educationc | 0.10 | Cramer’s V = 0.28 | |||
| High School or Less: Some College or More | 10:14 | 5:7 | 3:18 | ||
| Gender | NA | NA | |||
| Female:Male | 11:13 | 0:12 | 13:8 | ||
a
Mean of the age-equivalents for the Copying, Pattern Analysis, and Bead Memory subtests of the Stanford-Binet Intelligence Scale, 4th Edition (Thorndike, et al., 1986);
b
Based on a narrative language sample;
c
Paternal education level used for one participant in the DS group because maternal education level was unknown