We sought to identify the mechanisms that cause strongly fused individuals (those who have a powerful, visceral feeling of oneness with the group) to make extreme sacrifices for their group. A large multinational study revealed a widespread tendency for fused individuals to endorse making extreme sacrifices for their country. Nevertheless, when asked which of several groups they were most inclined to die for, most participants favored relatively small groups, such as family, over a large and extended group, such as country (Study 1).