What motivates devoted actors to extreme sacrifice, identity fusion, or sacred values?

Why do some individuals willingly make extreme sacrifices for their group? Whitehouse argues that such willingness stems from a visceral feeling of oneness with the group - identity fusion - that emerges from intense, shared dysphoric experiences or from perceived close kinship with others. Although Whitehouse's argument makes a valuable contribution to understanding extreme sacrifice, factors independent of identity fusion, such as devotion to sacred values, can predict self-sacrifice.