Theory and research suggest that people can increase their happiness through simple intentional positive activities, such as expressing gratitude or practicing kindness. Investigators have recently begun to study the optimal conditions under which positive activities increase happiness and the mechanisms by which these effects work. According to our positive-activity model, features of positive activities (e.g., their dosage and variety), features of persons (e.g., their motivation and effort), and person-activity fit moderate the effect of positive activities on well-being. Furthermore, the model posits four mediating variables: positive emotions, positive thoughts, positive behaviors, and need satisfaction. Empirical evidence supporting the model and future directions are discussed.

At the top of parents’ many wishes is for their children to be happy, to be good, and to be well-liked. Our findings suggest that these goals may not only be compatible but also reciprocal. In a longitudinal experiment conducted in 19 classrooms in Vancouver, 9- to 11-year olds were instructed to perform three acts of kindness (versus visit three places) per week over the course of 4 weeks. Students in both conditions improved in well-being, but students who performed kind acts experienced significantly bigger increases in peer acceptance (or sociometric popularity) than students who visited places. Increasing peer acceptance is a critical goal, as it is related to a variety of important academic and social outcomes, including reduced likelihood of being bullied. Teachers and interventionists can build on this study by introducing intentional prosocial activities into classrooms and recommending that such activities be performed regularly and purposefully.

When it comes to the pursuit of happiness, popular culture encourages a focus on oneself. By contrast, substantial evidence suggests that what consistently makes people happy is focusing prosocially on others. In the current study, we contrasted the mood-and well-being-boosting effects of prosocial behavior (i.e., doing acts of kindness for others or for the world) and self-oriented behavior (i.e., doing acts of kindness for oneself) in a 6-week longitudinal experiment. Across a diverse sample of participants (N ϭ 473), we found that the 2 types of prosocial behavior led to greater increases in psychological flourishing than did self-focused and neutral behavior. In addition, we provide evidence for mechanisms explaining the relative improvements in flourishing among those prompted to do acts of kindnessnamely, increases in positive emotions and decreases in negative emotions. Those assigned to engage in self-focused behavior did not report improved psychological flourishing, positive emotions, or negative emotions relative to controls. The results of this study contribute to a growing literature supporting the benefits of prosocial behavior and challenge the popular perception that focusing on oneself is an optimal strategy to boost one's mood. People striving for happiness may be tempted to treat themselves. Our results, however, suggest that they may be more successful if they opt to treat someone else instead.

A 4-week-long experiment examined the effects of a positive activity intervention in which students wrote about their ''best possible selves'' (BPS) once a week. We manipulated two factors that might affect the success of the happiness-increasing activity-whether the positive activity was administered online versus in-person and whether the participant read a persuasive peer testimonial before completing the activity. Our results indicated that the BPS activity significantly boosted positive affect and flow and marginally increased feelings of relatedness. No differences were found between participants who completed the positive activity online versus in-person. However, students who read a testimonial extolling the virtues of the BPS activity showed larger gains in wellbeing than those who read neutral information or completed a control task. The results lend legitimacy to online self-administered happiness-increasing activities and highlight the importance of participants' beliefs in the efficacy of such activities for optimum results.

Research shows that performing positive activities, such as expressing gratitude and doing acts of kindness, boosts happiness. But do specific positive activities work equally well across cultures? Our study examined the role of culture–activity fit by testing two positive activities across two cultures. Participants from the United States (n = 250) and South Korea (n = 270) were randomly assigned to express gratitude, perform kind acts, or engage in a neutral activity for the first half of a 6-week positive activity intervention. Multilevel growth modeling analyses revealed that the effect of practicing gratitude or kindness was moderated by culture: U.S. participants increased in well-being (WB) from both activities, γ11 = 0.19, SE = 0.06, t(511) = 3.04, p = .0006; γ12= 0.11, SE = 0.06, t(511) = 1.73, p = .03 (compared with the control group), but South Korean participants benefited significantly less from practicing gratitude than did U.S. participants, γ13 = −0.24, SE = 0.07, t(511) = −3.36, p = .002. South Korean participants, however, showed similar increases in WB as did U.S. participants when performing kind acts, γ14 = −0.06, SE = 0.07, t(511) = −0.82, ns. Finally, although greater self-reported effort yielded significantly larger increases in WB for U.S. participants, the effect of effort was not as strong for South Korean participants. We posit that, due to their dialectical philosophical tradition, South Koreans might have been more prone to feel mixed emotions (e.g., indebtedness and gratitude) while engaging in the gratitude letter activity than did U.S. participants.