Aggressive Acts Increase Commitment to New Groups :

How do individuals who switch between opposing sides develop a sense of commitment to their new groups? Study 1 examined these dynamics in a live-action tag game known as Humans versus Zombies, in which players transitioned from being Human to being Zombie, thus turning against their former fellow Humans. Study 2 examined data from professional basketball players in the NBA who moved to a new team and had to play against their former team. Aggressive acts against former group members in these competitive settings determined commitment to the new group above and beyond other factors. Aggressive acts against former teammates, such as simulated killing (Study 1) and blocked shots (Study 2), promoted more positive self-reported attitudes toward the new group (Study 1) and more collaboration with new group members in the form of assists (Study 2).