endogroup
A pair of concepts created by focusing on the tendency toward group closure and exclusiveness. A term used by the American sociologist W. G. Sumner. The in-group is the group with which an individual identifies himself/herself and feels a sense of belonging, whereas the out-group is the group to which one feels "others" and to which one is subject to competitiveness, conflict, hostility, and the like. In general, it is known that when the sense of belonging and attachment to the inner group increases and its cohesiveness increases, the rivalry and hostility toward the outer group tends to increase correspondingly. ---
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