Institutionalist Theory

This theory views the family as a social institution. Social institutions involve patterned ways of doing things shaped by widely-shared cultural understandings.

When we talk about the family as a social institution, hence, we are talking about set and shared ideas about marriage and what it means to be a family. These ideas are clear and consistent and people's intimate and family behaviours thus conform to broad patterns. When individuals violate norms around marriage and family, they may experience less social support from others (because they ways they are "doing family" don't conform to expectations) and/or dissatisfaction within families may be generated by norm violations.

Andrew Cherlin argues that marriage in North America has become deinstitutionalized (see Deinstitutionalization theory wiki page).