Table 4.
Means and standard deviations of GD patients’ and the controls’ total number of siblings, and numbers of older brothers, older sisters, younger brothers, and younger sisters
| GD boys (n = 94) | Control boys (n = 875) | Comparison testa | GD girls (n = 95) | Control girls (n = 914) | Comparison testa | |||
|---|---|---|---|---|---|---|---|---|
| Mean (SD) | Mean (SD) | t(df) | p | Mean (SD) | Mean (SD) | t(df) | p | |
| All siblings | 1.34 (0.87) | 1.36 (0.96) | 0.20 (967) | ns | 1.04 (0.89) | 1.40 (0.95) | 3.49 (1007) | .001 |
| Older brothers | 0.51 (0.70) | 0.34 (0.62) | −2.33 (109) | .022 | 0.25 (0.48) | 0.36 (0.63) | 1.98 (130) | ns |
| Older sisters | 0.17 (0.38) | 0.32 (0.58) | 3.54 (144) | .001 | 0.23 (0.49) | 0.33 (0.57) | 1.83 (122) | ns |
| Younger brothers | 0.44 (0.63) | 0.34 (0.59) | −1.47 (967) | ns | 0.20 (0.45) | 0.33 (0.56) | 2.70 (126) | .008 |
| Younger sisters | 0.22 (0.44) | 0.36 (0.59) | 2.71 (131) | .008 | 0.36 (0.58) | 0.37 (0.60) | 0.22 (1007) | ns |
aThe same number of subjects was used in each comparison for males and each comparison for females. Degrees of freedom (df) vary, however, because alternative versions of the t-tests were used, depending on whether Levene’s Test for Equality of Variances justified the assumption of equal variances. All p-values are two-tailed