Increasing prosocial behavior and decreasing selfishness in the lab and everyday life

The inherent tension between prosocial behavior and selfishness is central to understanding social interactions and conflicts. While laboratory studies using behavioral games have provided insights, their external validity is often questioned due to the artificiality of the experimental settings, typically involving interactions with strangers. This study aimed to bridge this gap by examining the impact of a psychological micro-intervention on prosocial behavior within naturally occurring relationships, specifically couples. The intervention targeted psychological flexibility, a set of skills encompassing awareness, openness, and commitment to values-congruent behaviors. The researchers hypothesized that the micro-intervention would increase prosocial choices in a behavioral game, exhibit a dose-response effect (i.e., greater impact when both partners receive the intervention), and lead to increased prosocial behaviors in daily life, as measured using event sampling methodology (ESM). The importance of this research lies in its potential to develop readily implementable interventions to promote prosociality in real-world settings.

Existing research on prosocial behavior has explored various factors influencing it, including personality traits, relationship closeness, game characteristics, and external manipulations like mood priming. However, studies actively intervening to enhance prosocial skills are limited. The focus has been on factors outside participants' direct control. This study uniquely addresses this gap by testing a micro-intervention targeting psychological flexibility, a skill set previously linked to health and well-being and shown to be related to socially related values and increased follow-through on those values. The use of ESM enhances ecological validity by capturing real-time experiences and reducing recall bias, providing a more comprehensive understanding of prosocial behavior in natural settings.

The study comprised two phases: a preliminary study and a larger replication study. The preliminary study randomized eight couples (n=16) into intervention and control groups, assessing prosocial behavior using the Dictator Game one week post-intervention. The main study expanded the design, randomizing 116 couples (n=232) into four groups: (1) both partners received the micro-intervention and ESM; (2) one partner received the micro-intervention and both partners completed ESM; (3) neither partner received the micro-intervention, but both completed ESM; (4) neither partner received the micro-intervention nor completed ESM. The Dictator Game, where participants divided 240 Francs worth of gift certificates, served as the primary measure of prosocial behavior in the laboratory. ESM involved five daily smartphone prompts assessing participants' prosocial actions towards their partners. The 15-minute micro-intervention focused on clarifying values and practicing skills promoting psychological flexibility (present moment awareness, acceptance). Data analysis employed multilevel models to account for the nested structure of the data (individuals within dyads, time points within individuals).

The preliminary study showed that couples in the intervention group allocated significantly more money (21.6% higher) to their partners in the Dictator Game compared to the control group. The main study replicated this finding and further revealed a dose-response effect: dyads where both partners received the intervention exhibited the highest levels of prosocial giving. Specifically, the mean amount given to partners was: Group 1 (both partners intervened): 144.5 Francs; Group 2 (one partner intervened): 133.8 Francs; Groups 3 & 4 (no intervention): 124.8 Francs. This difference was statistically significant (p = 0.014). Analyzing participants individually, those receiving the intervention gave significantly more (141.3 Francs) than those who did not (126.6 Francs, p = 0.024). The qualitative assessment of responses showed that 70.1% of participants responded fairly (50/50 split), 20.1% generously, and 9.8% selfishly; those in the intervention groups showed significantly more prosocial responses. ESM data revealed a non-significant linear trend in prosocial behavior across the week but a significant quadratic trend when considering the intervention group, showing an initial slight decline followed by a rise in prosocial behavior towards the end of the week. This contrasts with a steady decline among the non-intervention groups.

The findings strongly support the hypothesis that a brief psychological flexibility intervention effectively increases prosocial behavior and reduces selfishness. The dose-response effect indicates that the intervention is most effective when both partners participate. The results are consistent across laboratory and real-world settings, demonstrating good external validity. The higher rates of prosocial behavior in this study compared to previous Dictator Game studies using strangers might be attributed to the pre-existing relationship between participants, suggesting the importance of considering relationship context in future studies. This study adds to the literature by demonstrating the effectiveness of a brief, easily implementable intervention to promote prosociality. The integration of laboratory and ESM data allows for a more comprehensive understanding of the intervention's impact.

This study provides compelling evidence that a brief, easily administered psychological flexibility intervention can significantly enhance prosocial behavior and decrease selfishness in romantic couples. The consistent findings across laboratory and real-world contexts highlight the intervention's potential for broad application. Future research could investigate the long-term effects of this intervention, explore its efficacy in other relationship types, and examine underlying mechanisms in more detail.

While participants played for real money, the possibility of participants making decisions based on sharing intentions rather than monetary value cannot be entirely ruled out. The use of self-reported ESM data, although maximizing ecological validity and minimizing recall bias, is susceptible to some degree of self-report bias. Future studies could incorporate more objective measures of prosocial behavior to further strengthen the findings.