Table 1.
Demographic information about the Down syndrome (DS), Sex Chromosome Trisomy (XXY & XXX; +1X), and Typically Developing (TD) control groups.
| DS (n = 30) | +1X (n = 30) | TD (n = 30) | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| M | SD | Range | M | SD | Range | M | SD | Range | F or X2 | |
| Chron. Age | 11.34 | 3.02 | 7–17 | 11.61 | 3.29 | 5–18 | 11.28 | 2.69 | 6–17 | F(2, 87) < 1, p > 0.9 |
| Nonverbal IQ∧ | 52.41 | 13.2 | 40–87 | 100.75 | 15.70 | 74–135 | 110.37 | 11.97 | 86–139 | F(2, 84) = 150.56, p < 0.001 |
| Maternal Ed. | 15.68 | 2.17 | 11–21 | 15.57 | 1.79 | 12–19 | 16.13 | 2.26 | 12–21 | F(2, 87) < 1, p > 0.5 |
| n | % | n | % | n | % | |||||
| Sex—male | 15 | 50 | 15 | 50 | 15 | 50 | X2 < 1, p > 0.9 | |||
| Race/Ethnicity—WNH | 20 | 67 | 26 | 87 | 25 | 83 | X2(2) = 4.1, p > 0.12 | |||
∧DS group n = 29 with Nonverbal IQ data; +1X group, n = 28 with Nonverbal data; missing data on 3 participants total for Nonverbal IQ. Chron. Age, Chronological Age; Maternal Ed, Year of Maternal Education; WNH, White, Non-hispanic.