The proposed research consists of five studies examining relationships between chronic feelings of belonging with others (indexed by rejection sensitivity and self-esteem) and the regulation of belongingness across one's social network following social rejection. A new theoretical perspective is developed suggesting that chronic feelings of exclusion cause people to doubt the care of all close relationship partners following a single instance of rejection (belongingness-negation). In contrast, those who chronically feel included react by perceiving greater care from close others (belongingness-affirmation). Belongingness-affirmation and - negation are expected to explain (mediate) 1) main effects of rejection on state self-esteem and defensive derogation of the rejecter and 2) effects of chronic levels of belongingness on these reactions. In short, it is proposed that a single rejection can undermine or strengthen multiple close relationships, depending on the person's chronic sense of belongingness. Four studies test this model by experimentally manipulating rejection from strangers, romantic partners, or close others. A fifth tests the model in regard to day-to-day variations of naturally occurring events. [unreadable] [unreadable]