Human strategy updating in evolutionary games

TL;DR

This paper introduces a method to empirically measure human strategy update rules in evolutionary games, revealing frequent spontaneous changes that can inform more accurate models of cultural evolution.

Contribution

It presents an experimental approach to quantify human imitation-based strategy updates in spatially structured settings, bridging the gap between theoretical models and human behavior.

Findings

Spontaneous strategy changes are more frequent than in many models.

The experimental method allows detailed assessment of human update mechanisms.

Results can improve mathematical models of cultural evolution.

Abstract

Evolutionary game dynamics describes not only frequency dependent genetical evolution, but also cultural evolution in humans. In this context, successful strategies spread by imitation. It has been shown that the details of strategy update rules can have a crucial impact on evolutionary dynamics in theoretical models and e.g. significantly alter the level of cooperation in social dilemmas. But what kind of strategy update rules can describe imitation dynamics in humans? Here, we present a way to measure such strategy update rules in a behavioral experiment. We use a setting in which individuals are virtually arranged on a spatial lattice. This produces a large number of different strategic situations from which we can assess strategy updating. Most importantly, spontaneous strategy changes corresponding to mutations or exploration behavior are more frequent than assumed in many models. Our experimental approach to measure properties of the update mechanisms used in theoretical models will be useful for mathematical models of cultural evolution.