Zealot-driven dynamics of cooperation in link-specific strategy environments

Zealots — individuals who cooperate unconditionally — have been shown to suppress cooperation among normal players on lattices. However, this conclusion is typically derived under a node-strategy framework, in which individuals adopt a uniform strategy toward all neighbors. Here, we relax this assumption and examine how a minority of zealots shapes collective cooperation under a link-strategy framework, where individuals can respond differently to different interaction partners. We show that such interaction flexibility can reverse the cooperation-suppressing effect of zealots: once the fraction of link-strategy players exceeds a critical threshold, zealots instead promote cooperation. This cooperation-promoting effect is strongest when link-strategy players update their behavior through a balanced combination of direct experience and indirect social information. Excessive reliance on either source weakens the effect and can even restore the cooperation-suppressing influence of zealots. Together, these results show that the impact of zealots on collective cooperation depends not only on their presence, but also on individuals’ ability to tailor behavior across social ties and on how they integrate different sources of information when updating their strategies.