30 Philosophers, Chapter 10, Pyrrho of Elis, Touchstone 29: Social Constructs.

A social construct is a shared human-made idea that organizes life. It is a non-natural belief created and maintained by groups that shape reality. These are cultural blueprints that encompass shared ideas and frameworks. Many aspects of the world exist independently of humanity and are not social constructs, such as stars, animal reproduction, and gravity. In contrast, things that do not exist in nature and are social constructs include marriage, language, and money.

The idea has a long history across philosophy, sociology, anthropology, law, and cultural criticism. Related terms include social construction, convention, institution, norm, social agreement, social fact, and cultural framework. These overlap, but each carries a slightly different emphasis. A convention is a shared practice. A norm is an expected behavior. An institution is a stabilized social system. A social construct is the broader idea: a human-made framework that exists because minds and societies keep it in place.