Table 1.
Means, standard deviations, internal consistencies (Cronbach’s Alpha), and intercorrelations of study variables.
| Variable | 1 | 2 | 3 | 4 | 5 | 6 | |
|---|---|---|---|---|---|---|---|
| 1 | Age | – | |||||
| 2 | Gender a | 0.04 | – | ||||
| 3 | Work-related smartphone use (at home) | −0.01 | 0.03 | (0.84) | −0.02 | 0.14 | 0.11 |
| 4 | Sleep quality | 0.08 | 0.04 | −0.01 | – | −0.05 | −0.21 |
| 5 | Self-control demands (next day at work) | −0.09 | −0.05 | 0.19 | −0.01 | (0.93) | 0.47 |
| 6 | Ego depletion (next day at work) | −0.39 | −0.31 | 0.11 | −0.23 | 0.52 | (0.93) |
| M | 39.49 | 1.43 | 1.51 | 2.29 | 2.66 | 1.80 | |
| SD | 13.46 | 0.50 | 0.75 | 0.79 | 0.76 | 0.54 | |
Cronbach’s alpha for day-level variables represent the mean internal consistencies averaged over all measurement days. Correlations below the diagonal are person-level correlations (Nbetween = 63). Correlations above the diagonal are day-level correlations (Nwithin = 603). Numbers in bold p < 0.05. a Gender (1 = female, 2 = male).