The researchers studied how playing different types of games can affect how strongly people identify with their group. They had subjects play a game where they could choose to cooperate or not, and found that the type of game and the action chosen influenced how much people identified with their group. In games where cooperation was more attractive, people who cooperated with their group members felt a stronger sense of identity. This change in identity happened after the action was chosen, not before. Overall, actions that are seen as less competitive and more cooperative can enhance a person's sense of identity within a group.