Need for affiliation - Wikipedia
The need for affiliation ( N-Affil) is a term that was popularized by David McClelland and describes a person's need to feel a sense of involvement and "belonging" within a social group; McClelland's thinking was strongly influenced by the pioneering work of Henry Murray who first identified underlying psychological human needs and motivational processes (1938).
https://en.wikipedia.org/wiki/Need_for_affiliation