Do descriptive social norms drive peer punishment? Conditional punishment strategies and their impact on cooperation

Peer punishment is widely considered a key mechanism supporting cooperation in human groups. Although much research shows that behavior shaped by the prevailing social norms, little known about how decisions are impacted context. We present set of large-scale incentivized experiments which participants (999 American recruited via Amazon Mechanical Turk) could punish their partner conditional on either level or displayed others who previously interacted same setting. While many independently levels punishment, substantial portion punishes free riding more severely when common (‘norm enforcement’), punished (‘conformist punishment’). With dynamic model we demonstrate strategies can substantially promote cooperation. In particular, conformist helps to gain foothold population, and norm enforcement maintain at high levels. Our results provide solid empirical evidence illustrate possible implications for dynamics