Humans are considered a highly cooperative species. Through cooperation, we can tackle shared problems like climate change or pandemics and cater for shared needs like shelter, mobility, or healthcare. However, cooperation invites free-riding and can easily break down. Maybe because of this reason, societies also enable individuals to solve shared problems individually, like in the case of private healthcare plans or private retirement planning. Such “self-reliance” allows individuals to avoid problems related to public goods provision, like free-riding or underprovision, and decreases social interdependence. However, not everyone can equally afford to be self-reliant, and amid shared problems, self-reliance may lead to conflicts within groups on how to solve shared problems. In two preregistered studies, we investigate how the ability of self-reliance influences collective action and cooperation. We show that self-reliance crowds out cooperation and exacerbates inequality, especially when some heavily depend on collective action while others do not. However, we also show that groups are willing to curtail their ability of self-reliance. When given the opportunity, groups overwhelmingly vote in favor of abolishing individual solutions to shared problems, which, in turn, increases cooperation and decreases inequality, particularly between group members that differ in their ability to be self-reliant. The support for such endogenously imposed interdependence, however, reduces when individual solutions become more affordable, resonating with findings of increased individualism in wealthier societies and suggesting a link between wealth inequality and favoring individual independence and freedom over communalism and interdependence.

人类被认为是高度合作的物种。通过合作，我们可以解决气候变化或大流行等共同问题，并满足住房，流动性或医疗保健等共同需求。但是，合作会导致搭便车，并且很容易破裂。也许由于这个原因，社会也使个人能够单独解决共同的问题，例如在私人医疗保健计划或私人退休计划中。这种“自力更生”使个人避免了与公共物品提供有关的问题，如搭便车或准备不足，并减少了社会相互依存。但是，并不是每个人都能负担得起自力更生，在共同的问题之中，自力更生可能导致小组内部就如何解决共同的问题发生冲突。在两项预先注册的研究中，我们研究了自力更生的能力如何影响集体行动与合作。我们表明，自力更生会挤垮合作并加剧不平等，特别是当某些人严重依赖集体行动而另一些人不依赖集体行动时。但是，我们也表明，群体愿意减少其自力更生的能力。当有机会时，团体以压倒多数投票赞成废除对共同问题的个别解决方案，从而反过来增加了合作并减少了不平等，特别是在自力更生的团体成员之间。但是，当各个解决方案变得更加负担得起时，对这种内在施加的相互依赖性的支持就会减少，