groupism
/ˈɡruːpɪz(ə)m/noun
1The desire to belong to a group; the tendency to form factions (now chiefly Indian English ). Also: the tendency to view people as members of a group, rather than as individuals.
2With capital initial: the principles or practice of the Oxford Group Movement. Now historical and rare.
Origin
Mid 19th century. From group + -ism.