Table 2.
Between-Sex T-Tests in Sleep Measures (N = 3,058)
| Female | Male | Male vs. Female | ||||
|---|---|---|---|---|---|---|
| M | SD | M | SD | t (df) | d | |
| Bedtime | ||||||
| School nighta | 23:21 | 1.13 | 23:23 | 1.11 | .86 (3056) | .03 |
| Weekend nightb | 0:23 | 1.86 | 0:38 | 1.94 | 3.56*** (3056) | .13 |
| Wake time | ||||||
| School morning | 6:16 | .81 | 6:24 | .88 | 4.08*** (3055.8)e | .15 |
| Weekend morning | 9:46 | 1.77 | 9:42 | 1.91 | −1.06 (3055.8)e | −.04 |
| TST (hrs) | ||||||
| School night | 7.93 | 1.23 | 8.02 | 1.24 | 2.02* (3056) | .07 |
| Weekend night | 9.38 | 1.93 | 9.07 | 2.11 | 4.32*** (3054.4)e | .16 |
| Chronotypec | 4:33 | 1.67 | 4:47 | 1.72 | 3.78*** (3056) | .14 |
| Social jetlag (hrs)d | 2.80 | 1.46 | 2.81 | 1.46 | .26 (3056) | .01 |
a
Sunday-Thursday night.
b
Friday-Saturday night.
c
Midpoint of sleep on weekend nights corrected for sleep debt; measure of chronotype. Calculated as midpoint of sleep on weekend nights − .5*(TST Weekend − (5*TST School + 2*TST Weekend) / 7 (Roenneberg et al., 2004).
d
Calculated as | midpoint of sleep on weekend nights – midpoint of sleep on school nights | (Wittman et al., 2006).
e
Degrees of freedom corrected for heterogeneity of variance.
TST—total sleep time.
*
p < .05, two-tailed.
***
p < .001, two-tailed.