I will hold a weapon if you hold one: Experiments of preemptive strike game with possession option

Force possession in an inter-personal or inter-group context has been a familiar issue in human evolution and continues to be important today. The puzzle around force possession is that it may result in escalation of force and increase the risk of being attacked even if the force possession is originally intended for self-defense. However, there are few relevant empirical studies. This study examined the determinants of force possession by developing the preemptive strike game to include a possession option. In this game, each player (who is matched with one opponent) decides whether to possess an attack button and, if they possess, they can decide whether to push the button (attack the opponent). If neither the player nor the opponent attack, nothing happens, but if a player attacks first, the player loses a small amount of resources, but the one who is attacked loses significant resources. In this situation, possessing the button raise the potential risk of being attacked due to fear. In Study 1, 182 participants (online crowd workers) played the game, and the results showed the tendency to seek a balance of forces, that is, the higher the opponent's expected probability of possession, the more likely participants were to decide to possess. However, the opponent's probability of possession was the measured expectations by the participants. To clarify the causality, in Study 2 with 131 participants (online crowd workers), we experimentally manipulated the probability of the opponent's possession, and confirmed the same tendency. We discuss the implications and the limitations.