When Lone Wolf Defectors Undermine the Power of the Opt-Out Default

Eamonn Ferguson,Jonathan H W Tan,Ruslan Shichman

doi:10.1038/s41598-020-65163-1

Eamonn Ferguson, Jonathan H W Tan + Show 1 more

Open Access

https://doi.org/10.1038/s41598-020-65163-1

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Abstract

High levels of cooperation are a central feature of human society, and conditional cooperation has been proposed as one proximal mechanism to support this. The counterforce of free-riding can, however, undermine cooperation and as such a number of external mechanisms have been proposed to ameliorate the effects of free-riding. One such mechanism is setting cooperation as the default (i.e., an opt-out default). We posit, however, that in dynamic settings where people can observe and condition their actions on others’ behaviour, ‘lone wolf’ defectors undermine initial cooperation encouraged by an opt-out default, while ‘good shepherds’ defeat the free-riding encouraged by an opt-in default. Thus, we examine the dynamic emergence of conditional cooperation under different default settings. Specifically, we develop a game theoretical model to analyse cooperation under defaults for cooperation (opt-out) and defection (opt-in). The model predicts that the ‘lone wolf’ effect is stronger than the ‘good shepherd’ effect, which – if anticipated by players – should strategically deter free-riding under opt-out and cooperation under opt-in. Our experimental games confirm the existence of both ‘lone wolf’ defectors and ‘good shepherd’ cooperators, and that the ‘lone wolf’effect is stronger in the context of organ donation registration behaviour. We thus show a potential ‘dark side’ to conditional cooperation (‘lone wolf effect’) and draw implications for the adoption of an opt-out organ donation policy.

Highlights

The high levels of cooperation observed across all human societies[1,2,3,4] are hard to explain from the perspective of natural selection: why would someone perform a behaviour that benefits another at a personal cost3,4? To address this problem a number of ultimate (‘why’) explanations, supported by a number of proximal (‘how’) mechanisms, have been proposed[2,3,4,5,6,7]
These results extend our understanding of the dynamics of conditional cooperation and show it is influenced by the nature of the cooperative context
Conditional cooperation across rounds is observed. This pattern is modified by the type of cooperative or free-riding context. When it is a cooperative context and people choose to leave, immediate individualistic feedback enhances negative conditional cooperation resulting in people following suit and leaving

Summary

Introduction

We show that contrary to equilibrium predictions under self-interest, the ‘good shepherd’ increases cooperation by leading conditional cooperators thereby defeating free riding, and cooperative behaviour as signalled by an opt-out default policy is undermined over time when conditional cooperators can observe and follow ‘lone-wolf ’ defection. We hypothesized that a stronger ‘lone-wolf ’ effect would be observed when people could update their behaviour based on feedback of others’ behaviour before each round ends and payoffs accrue.

Results

Conclusion