Final answer:
Spectators reinforce the 'other' identity of killers, highlighting social phenomena like dehumanization and confirmation bias that foster segregation through stereotyping and prejudice.
Step-by-step explanation:
Linnemann points out that spectators often use the killers' identity to reinforce their identities as "the other", exemplifying the social phenomena of creating binary oppositions between us and them. Such methods of establishing identity boundaries are prevalent and can be expressed through various forms, such as dehumanization during extreme acts like genocide, or through less violent but equally divisive means like symbolization and the reinforcement of stereotypes. Additionally, in sociology, confirmation bias and in-group bias demonstrate how individuals might reinforce existing prejudices by seeking information that supports their stereotypical views and ignoring contradicting evidence. This cycle of prejudice can be perpetuated by various societal factors that include historical, cultural, and social elements.