Data from: Extortion strategies resist disciplining when higher competitiveness is rewarded with extra gain

Cooperative strategies are predicted for repeated social interactions. The
recently described Zero Determinant (ZD) strategies enforce the partner’s
cooperation because the ‘generous’ ZD players help their cooperative
partners while ‘extortionate’ ZD players exploit their partners’
cooperation. Partners may accede to extortion because it pays them to do
so, but the partner can sabotage his own and his extortioner’s score by
defecting to discipline the extortioner. Thus, extortion is predicted to
turn into generous and disappear. Here, we show with human volunteers that
an additional monetary incentive (bonus) paid to the finally competitively
superior player maintains extortion. Unexpectedly, extortioners refused to
become disciplined, thus forcing partners to accede. Occasional opposition
reduced the extortioners’ gain so that using extortion paid off only
because of the bonus. With no bonus incentive, players used the generous
ZD strategy. Our findings suggest that extortion strategies can prevail
when higher competitiveness is rewarded with extra gain.