social (adj.)
c.1500 (implied in socially), “characterized by friendliness or geniality,” also “allied, associated,” from M.Fr. social (14c.), from L. socialis “united, living with others,” from socius “companion,” probably originally “follower,” and related to sequi “to follow” (cf. O.E. secg, O.N. seggr “companion,” which seem to have been formed on the same notion; see sequel). Meaning “living or liking to live with others, disposed to friendly intercourse” is attested from 1729. Meaning “pertaining to society as a natural condition of human life” first attested 1695, in Locke.
Social climber is from 1926; social work is 1890; social worker 1904. Social drink(ing) first attested 1976. Social studies as an inclusive term for history, geography, economics, etc., is attested from 1938. Social security “system of state support for needy citizens” is attested from 1908. Social butterfly is from 1910, in figurative reference to “flitting.” Social contract is from Rousseau. Social Darwinism attested from 1887. Social engineering attested from 1899. Social science is from 1811. In late 19c. newspapers, social evil is “prostitution.” Social justice is attested by 1718; social network by 1971; social networking by 1984.