The strategy method conflates confusion with conditional cooperation in public goods games: evidence from large scale replications

The strategy method is often used in public goods games to measure individuals’ willingness to cooperate depending on the level of cooperation by others (conditional cooperation). However, while the strategy method is informative, it risks being suggestive and inducing elevated levels of conditional cooperation that are not motivated by concerns for fairness, especially in uncertain or confused participants. Here we make 845 participants complete the strategy method two times, once with human and once with computerized groupmates. Cooperation with computers cannot rationally be motivated by concerns for fairness. Worryingly, 69% of participants conditionally cooperated with computers, whereas only 7% conditionally cooperated with humans while not cooperating with computers. Overall, 83% of participants cooperated with computers, contributing 89% as much as towards humans. Results from games with computers present a serious problem for measuring social behaviors.