Table 1.
Differences in age, sex, income, education, and fluid intelligence between groups
| All HSS | All MLS | |||||||
|---|---|---|---|---|---|---|---|---|
| Variable | n | M | SD | n | M | SD | t | P |
| Age | 362 | 28.86 | 3.61 | 708 | 28.71 | 3.73 | 0.63 | 0.53 |
| Female | 180 | 394 | −1.84 | 0.07 | ||||
| Male | 182 | 314 | ||||||
| Income | 360 | 4.73** | 2.09 | 705 | 5.16 | 2.19 | −3.08 | 0.002 |
| Education | 362 | 14.43*** | 1.87 | 707 | 15.09 | 1.73 | −5.78 | <0.001 |
| Fluid intelligence CR | 362 | 15.73*** | 4.97 | 707 | 17.09 | 4.78 | −4.35 | <0.001 |
| HSS-NRD | MLS-NRD | |||||||
| n | M | SD | n | M | SD | |||
| Age | 142 | 28.70 | 3.75 | 381 | 28.78 | 3.75 | −0.20 | 0.84 |
| Female | 64* | 220 | −2.60 | 0.01 | ||||
| Male | 78* | 161 | ||||||
| Income | 142 | 4.92 | 2.09 | 380 | 5.31 | 2.13 | −1.86 | 0.06 |
| Education | 142 | 14.32*** | 1.95 | 380 | 15.05 | 1.73 | −4.17 | <0.001 |
| Fluid intelligence CR | 142 | 14.88*** | 4.87 | 380 | 16.75 | 4.89 | −3.89 | <0.001 |
| HSS-RD | MLS-RD | |||||||
| n | M | SD | n | M | SD | |||
| Age | 220 | 28.97 | 3.53 | 327 | 28.64 | 3.71 | 1.04 | 0.30 |
| Female | 116 | 174 | −0.11 | 0.91 | ||||
| Male | 104 | 153 | ||||||
| Income | 218 | 4.60 | 2.09 | 325 | 4.98 | 2.24 | −1.98 | 0.05 |
| Education | 220 | 14.50*** | 1.82 | 327 | 15.13 | 1.74 | −4.14 | <0.001 |
| Fluid intelligence CR | 220 | 16.28** | 4.97 | 327 | 17.49 | 4.62 | −2.91 | 0.004 |
HSS, habitual short sleepers; MLS, medium length sleepers; NRD, not reporting daytime dysfunction; RD, reporting daytime dysfunction; n, subsample size; M, mean; CR, correct responses. Bolded comparisons were significant after p < 0.01 false discovery rate correction.
**p < 0.01, ***p < 0.001.