There are various kinds of social motivation. One type of social motivation is the need to affiliate, or belong to a group. How can evolutionary theory, drive-reduction theory, and arousal theory explain our need for affiliation?

evolutionary theory- social bonds protected our ancestors. Parents who had good relationships with their children had incentive to survive, and once those children reached adulthood they felt a need to reproduce and nurture their own offspring. Our ancestors stayed in large groups while hunting and gathering to protect themselves from predators. We are genetically predisposed to be social creatures due to our ancestors who felt a need to belong mating.

Drive-reduction theory- people feel the need to belong due to the drive to achieve homeostasis. When people feel they have not satisfied their need to belong and feel emotional pain, they feel physiological pain in the anterior cingulate cortex, the same area that is activated when physical pain is felt

Arousal theory- people attempt to find the right level of stimulation by using the need to belong. People report feeling happiness and self-esteem when their need to belong is satisfied. They feel joy, which is the right level of stimulation.

(I hope this helps. This was a difficult question that no one else seemed to be helping with all parts of!)