Study title

United Kingdom

Individual

1. Modified Public Goods Game in which participants contributed effort (grip squeezes) instead of tokens.2. Online chatThe details of the methods are as follows:The basic experimental set up was based on an established behavioural economics paradigm of a Public Goods Game. In the standard version of the game participants are given a number of tokens and are then asked to choose how many of these tokens to put into a public pot. The tokens in this pot are then multiplied by a factor (greater than one and less than the number of players) and this ‘public good’ is divided evenly between participants. Two modifications to this game were made in this project: 1) instead of contributing tokens, participants were asked to contribute physical effort (hand grip squeezes), and 2) the amount of effort exerted by participants determined the monetary reward received at the end of the experiment. For practical reasons (equipment limitations), participants were not exerting effort simultaneously, but rather each participant attended the experimental session individually. A group was formed of four participants in a row, and the final payout was depend on their combined performance. The experimental set up was as follows: 1) Each participant was assigned to a group of five people and asked to attend two experimental sessions (Round 1 and Round 2) individually. During each experimental session participants were required to exert effort by squeezing a handgrip device 40 times. Each squeeze was associated with a small monetary reward. Participants had to decide how they wanted to distribute the proceeds from the effort trials – they could keep them for themselves or put them in a public pot. Proceeds in the public pot would be multiplied by 1.5 and divided evenly between all group members.2) Upon arrival to an experimental session, participants were given an opportunity to experience how effortful the task was by squeezing the hand grip device ten times.3) Then, participants were asked to indicate how many effortful trials out of 40 they wanted to complete for their own benefit, and how many they wanted to contribute to the public pot (Intended Contributions). 4) This was followed by the execution phase, during which participants were required to squeeze the handgrip device. They either started by squeezing for individual or group pot, and were told they could switch the pot at any point by pressing the ‘s’ button on a keyboard. Number of trials participants performed for the individual and public pots was recorded (Actual Contributions) 5) After each experimental session, participants took part in an anonymous online chat with other members of their group, where information about individual contributions and group performance (wins) was shared and discussedParticipants: Participants were recruited using Queen Mary Research Volunteers scheme at Queen Mary University of London and the word of mouth. Ninety participants completed the study