What’s the difference between social and societal? Not much, but enough that you may become the victim of social stigma if you ignore subtle societal signals.
Societal is the pedantic alternative to social. They both mean “pertaining to society,” but as the latter word, first attested in the Middle Ages, was increasingly used in the modern era to refer to interpersonal contact rather than in the context of complex forces within human populations, societal appeared in the latter part of the nineteenth century as a more serious, scholarly alternative. It is mostly seen in such usage and is otherwise considered pretentious.
Even now, social is more likely to appear in phrases referring to individuals, not groups, such as “social disposition,” “social engagement,” and “social life.” Societal, on the other hand, is employed in contexts like “societal pressure to conform,” though social still has the same import in usage such as “social institutions,” which refers to widespread traditions, not venues where people hang out.
Standing phrases that include social also include “social climber,” referring to a person who tries to rise above his or her station in life; “social disease,” a euphemism for “venereal disease” (one spread through sexual contact), or any disease whose distribution is related to socioeconomic factors; and “social drinker,” which denotes a regular imbiber of alcoholic beverages whose indulgence is not considered excessive.
The most ubiquitous such phrase of the last decade or so, however, is “social network(ing),” a case of an unfortunate usurpation of a useful term for a diluted sense: In most contexts, a social network is a virtual web of friends, acquaintances, and colleagues or professional contacts, enabled by recent technological innovations, that is widely seen as contributing to a more expansive yet much more superficial outlook on interpersonal communication and interaction than was prevalent in the past. (Yet the telephone, the telegram, and other once innovative devices were in their day similarly derided for weakening the social contract.)
More provocative phrases are “social Darwinism,” the name for the theory that some social groups are biologically superior to others, and “social engineering,” which has two senses: large-scale manipulation or influencing of society, or deceptive collection of confidential personal information.
The ancestor of both words is socius, Latin for “accomplice,” “ally,” or “companion.” Other terms that stem from this parentage include sociology, which primarily means “the study of aspects of large groups of people” — the more far-reaching equivalent of psychology, which focuses on the behavior of individuals — and socialite, a mildly pejorative term for a person with prominent status in society, usually as a result of abundant wealth. Antisocial, meanwhile, denotes behavior averse or hostile to society, and asocial refers to someone who avoids engaging in society.
Socialism is a term coined in the mid-nineteenth century to apply to sometimes competing ideas of governance, often similar to and often confused with those of communism, in which the state controls production and distribution of goods and services.
A related term is association, referring to networks of relationships. Interestingly, this term is the origin of a word for the globally popular sport known in most of the world as football (or a transliteration such as fussball or futbol) but in the United States called soccer: Originally, this game, to distinguish it from rugby football (now usually called simply rugby), was termed “association football.” Slang usage shortened this term to assoc and later soccer.