Literally hurts to be isolated or rejected. Need-to-belong theory: we have biological based need for interpersonal connections. Often look to others when situation is ambiguous to figure out what to believe and how to act. Social roles: clusters of social norms associated with social category. Social norm violations typically breach some social ritual. Impression management: adjust actions to influence how others perceive you. Social facilitation: simple tasks or familiar tasks can enhance performance. Social disruption: arousal interferes with performance on complex or new tasks. Seek to evaluate abilities and beliefs by comparing them with others. Upward social comparison: comparing to superiors, motivation. Downward social comparison: comparing to inferiors, feels good man lol. People"s tendency to slack off in groups. Diffusion of responsibility: the amount of responsibility distributed among the group. Bystander nonintervention: presence of others makes us less, not more likely to help. Tendency of people to alter behavior as result of group pressure.