Objectives: Various positive psychology interventions have been experimentally tested, but only few studies addressed the effects of such activities in participants aged 50 and above. Method: We tested the impact of four self-administered positive psychology interventions in an online setting (i.e., gratitude visit, three good things, three funny things, and using signature strengths in a new way) on happiness and depressive symptoms in comparison with a placebo control exercise (i.e., early memories). A total of 163 females aged 50-79 tried the assigned interventions or the placebo control exercise for one week and completed measures on happiness and depressive symptoms at five times (pre-and post-test, 1, 3, and 6 months). Results: Three out of the four interventions (i.e., gratitude visit, three good things, and using signature strengths in a new way) increased happiness, whereas two interventions (three funny things and using signature strengths in a new way) led to a reduction of depressive symptoms on at one post-measure. Conclusion: Positive psychology interventions yield similar results for people aged 50 and above as for younger people. The dissemination of such interventions via the Internet offers a valuable opportunity for older age groups as well.

Recent years have seen an increasing interest in research in positive psychology interventions. There is broad evidence for their effectiveness in increasing well-being and ameliorating depression. Intentional activities that focus on those character strengths, which are most typical for a person (i.e., signature strengths, SS) and encourage their usage in a new way have been identified as highly effective. The current study aims at comparing an intervention aimed at using SS with one on using individual low scoring (or lesser) strengths in a randomized placebo-controlled trial. A total of 375 adults were randomly assigned to one of the two intervention conditions [i.e., using five signature vs. five lesser strengths (LS) in a new way] or a placebo control condition (i.e., early memories). We measured happiness and depressive symptoms at five time points (i.e., pre- and post-test, 1-, 3-, and 6-months follow-ups) and character strengths at pre-test. The main findings are that (1) there were increases in happiness for up to 3 months and decreases in depressive symptoms in the short term in both intervention conditions; (2) participants found working with strengths equally rewarding (enjoyment and benefit) in both conditions; (3) those participants that reported generally higher levels of strengths benefitted more from working on LS rather than SS and those with comparatively lower levels of strengths tended to benefit more from working on SS; and (4) deviations from an average profile derived from a large sample of German-speakers completing the Values-in-Action Inventory of Strengths were associated with greater benefit from the interventions in the SS-condition. We conclude that working on character strengths is effective for increasing happiness and discuss how these interventions could be tailored to the individual for promoting their effectiveness.

Most tested indicators of a person × intervention fit are robust predictors of happiness and depressive symptoms-even after 3.5 years. They might serve for an early estimation of the effectiveness of a positive intervention.

While correlational evidence exists that humor is positively associated with well-being, only few studies addressed causality. We tested the effects of five humor-based activities on happiness and depression in a placebo-controlled, self-administered online positive psychology intervention study (N = 632 adults). All of the five one-week interventions enhanced happiness, three for up to six months (i.e. three funny things, applying humor, and counting funny things), whereas there were only shortterm effects on depression (all were effective directly after the intervention). Additionally, we tested the moderating role of indicators of a person × intervention-fit and identified early changes in well-being and preference (liking of the intervention) as the most potent indicators for changes six months after the intervention. Overall, we were able to replicate existing work, but also extend knowledge in the field by testing newly developed interventions for the first time. While correlational evidence exists that humor is positively associated with well-being, only few studies addressed causality. We tested the effects of five humor-based activities on happiness and depression in a placebo-controlled, self-administered online positive psychology intervention (PPI) study (N = 632 adults). All of the five one-week interventions enhanced happiness, three for up to six months (i.e., three funny things, applying humor, and counting funny things), whereas there were only short-term effects on depression (all were effective directly after the intervention). Additionally, we tested the moderating role of indicators of a person×intervention-fit and identified early changes in well-being and preference (liking of the intervention) as the most potent indicators for changes six months after the intervention. Overall, we were able to replicate existing work, but also extend knowledge in the field by testing newly developed interventions for the first time. Findings are discussed with respect to the current literature.

Character strengths were tested in relation to subjective (life satisfaction) and physical (selfevaluated health and physical fitness) well-being (440 adults). Health-behaviors and the mediating role of health-behaviors in explaining the relationship between character and well-being were also considered. Emotional, intellectual strengths and strengths of the heart were positively associated with life satisfaction and physical fitness. Emotional strengths correlated positively with the self-evaluation of feeling healthy. All strengths (except for modesty and religiousness) were related to health-behaviors; e.g. healthy eating and watching ones food consumption were associated with self-regulation and intellectual strengths. Health behaviors partially mediated the relation of broader strengths factors on subjective and physical well-being. The largest indirect effects were found for leading an active way of life. The study suggests that there are positive relations between character strengths and subjective but also physical well-being. Furthermore, potential mechanisms, which might account for these relations (i.e. health-behaviors) are assessed. AbstractCharacter strengths were tested in relation to subjective (life satisfaction) and physical