Table 3.
The Effects of Trait Gratitude and Trait Optimism on Daily Outcomes
| Separate predictors |
Simultaneous predictors |
|||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Gratitude |
Optimism |
Gratitude |
Optimism |
Comparison |
||||||||||||
| Outcome variable | b | t | p | rb (f) | b | t | p | rb (f) | b | t | p | b | t | p | z | p |
| Physiology | ||||||||||||||||
| Heart Rate | −1.18 | 7.13 | <.001 | .13 | −1.25 | 7.51 | < .001 | .19 | −.71 | 3.52 | <.001 | −.85 | 4.23 | <.001 | .42 | .676 |
| Systolic blood pressure | −1.12 | 3.93 | <.001 | .05 | −1.02 | 3.53 | < .001 | .02 | −.81 | 2.37 | .018 | −.57 | 1.63 | .103 | −.40 | .689 |
| Diastolic blood pressure | −.94 | 4.69 | <.001 | .09 | −.58 | 2.82 | .005 | .05 | −.91 | 3.75 | <.001 | −.07 | .27 | .786 | −1.96 | .051 |
| Health behaviors | ||||||||||||||||
| Sleep quality | .09 | 8.45 | <.001 | .24 | .13 | 11.66 | <.001 | .34 | .03 | 2.65 | .008 | .11 | 8.34 | <.001 | −3.27 | .001 |
| Moderate physical exercise | .14 | 4.26 | <.001 | .12 | .15 | 4.44 | <.001 | .14 | .09 | 2.16 | .031 | .10 | 2.50 | .013 | −.21 | .832 |
| Vigorous physical exercise | .10 | 3.63 | <.001 | .08 | .09 | 3.32 | <.001 | .10 | .07 | 2.16 | .031 | .05 | 1.57 | .116 | .32 | .752 |
| Stress | ||||||||||||||||
| Stress frequency* | .87 | 6.45 | <.001 | .80 | 10.95 | <.001 | .99 | .44 | .658 | .80 | 8.83 | <.001 | 4.44 | <.001 | ||
| Stress intensity | −.05 | 3.73 | <.001 | .06 | −.10 | 8.45 | <.001 | .22 | .02 | 1.11 | .268 | −.11 | 7.64 | <.001 | 4.98 | <.001 |
| Expectations and reflections | ||||||||||||||||
| Expectations for day | .22 | 12.55 | <.001 | .45 | .24 | 13.46 | <.001 | .49 | .13 | 6.34 | <.001 | .17 | 7.88 | <.001 | −.92 | .356 |
| Best part of day | .44 | 15.68 | <.001 | .39 | .31 | 10.60 | <.001 | .26 | .39 | 11.55 | <.001 | .09 | 2.63 | .009 | 4.97 | <.001 |
| Worst part of day | −.23 | 6.93 | <.001 | .20 | − .41 | 12.21 | <.001 | .38 | −.02 | .40 | .690 | −.40 | 9.92 | <.001 | 5.45 | <.001 |
| Appreciation toward others | .65 | 14.37 | <.001 | .39 | .40 | 8.32 | <.001 | .24 | .62 | 11.53 | <.001 | .06 | 1.09 | .275 | 5.88 | <.001 |
Note. In the far right columns, we created a contrast that subtracted optimism from gratitude. A positive value indicates that the gratitude coefficient is more positive than the optimism coefficient, and a negative value indicates that the optimism coefficient is more positive than the gratitude coefficient. Effect size estimates were calculated using a method explained by Rights and Sterba (2019). The rb(f) statistic is analogous to the square root of the reduction in variance method initially described by Raudenbush and Bryk (2002), akin to a correlation. Due to space constraints, 95% confidence intervals are reported in supplemental Table 1.
For the models that included stress frequency as a dichotomous outcome, we calculated odds ratios using a multilevel model for binomial outcomes (odds ratios and z statistics replace b and t statistics for this outcome).