Recent research on consumption and subjective well-being has revealed that experiential purchases and prosocial spending promote happiness by enhancing the purchasers' social relationships. This study (N = 1,523) explored whether undergraduate students' consumption behaviors during summer break would be associated with their post-break happiness, and whether the consumption-happiness relationship would be mediated by a positive influence on their social relationships. The results showed that both experiential purchases and prosocial spending during summer break were associated with greater post-break happiness, but only when these purchases had a positive influence on the purchasers' social relationships. These effects remained significant after controlling for respondents' personality traits, financial standing, and sex. Moreover, both experiential purchases and prosocial spending were more likely to have a positive influence on social relationships than luxury purchases. These results are congruent with the recent exposition that experiential purchases and prosocial spending promote happiness by enhancing the purchasers' social relationships.

a b s t r a c t a r t i c l e i n f oDue to the ever-present allure of potentially more appealing or attractive partners, people in mutually committed relationships face a commitment problem (i.e., uncertainty about partner fidelity). This problem exists for both friendship and romantic relationships. In an exploratory pilot study, participants described real-life commitment-confirming incidents in either friendship or romantic relationships. The results revealed that the same types of pro-relationship acts (e.g., throwing a surprise party) were used to communicate commitment to one's partner in both types of relationship. Using signaling theory, we predicted that costly commitment signals would be more effective than non-costly commitment signals (Hypothesis 1). Also, we predicted that failure to engage in such behaviors would communicate non-commitment, and that such failures would have a more detrimental effect on romantic relationships than friendship (Hypothesis 2). Two scenario experiments (study 1 in Japan and study 2 in the U.S.) were conducted to test these hypotheses. The results showed that costly commitment signals were more effective than non-costly commitment signals in both Japan and the U.S. In addition, the absence of situationally appropriate commitment signals (e.g., forgetting a special occasion) was substantially more damaging to romantic relationships than to friendship.

A facile generation of organic solvents of anhydrous grade can be performed by distillation from sodium–benzophenone ketyl, which is prepared from commercial sodium dispersion and benzophenone. The distilled tetrahydrofuran, diethyl ether, hexane, 1,2-dimethoxyethane, and 1,4-dioxane with water contents less than 10 ppm were obtained by a simple protocol. Safe treatment of the distillation residue also was simply achieved by the addition of methanol. The protocol suits for providing a small amount of an anhydrous solvent at the laboratory scale.

Acknowledgement We are grateful to Yuka Ikko, Soichi Izumi, Sae Kamada and Daisuke Nakanishi for their assistance with the data collection. We also thank Robert Kurzban and the three reviewers who provided valuable comments on earlier manuscripts. This research was supported by the Japan Society for the Promotion of Science (No. 21683006) and the Uehiro Foundation of Ethics and Education.

No abstract