Why Opt-Out Defaults Diminish Living Organ Donations

Opt-out defaults can motivate people towards more prosocial behavior and many countries have adopted opt-out defaults to increase deceased organ donation, energy conservation, or childhood vaccination. Prior studies show that opt-out defaults are powerful for increasing a specific cooperative behavior (e.g., deceased organ donation). However, little is known about how they may spillover to influence related cooperative behaviors (e.g., living organ donation) and how they may interact with mechanisms known to support human cooperation (e.g., inclusive fitness and reputation building). The present research addresses these gaps by investigating how an opt-out default policy for deceased organ donation influences the supply of living organs and how exposure to different default policies (opt-in or opt-out) alters perceptions of trust in others, inclusive fitness, and reputation building considerations. Across three studies, we show that the cooperative opt-out defaults for deceased organ donations have negative spillover-effects on living donations, which are larger for people with stronger pure altruistic tendencies. We show that this negative spillover effect is due to enhanced trust that organ supply approaches demand under opt-out. We further show that this interpretative change in organ supply leads to reduced living organ donations by (i) undermining the reputation-building effect of living organ donation and (ii) making people less willing to donate a living organ to recipients low in genetic relatedness and emotional closeness. The study’s findings have important implications for policymakers who aim to increase human cooperation by setting cooperative defaults.