Monogamy

Monogamy (/məˈnɒɡəmi/ mə-NOG-ə-mee) is a relationship of two individuals in which they form a mutual and exclusive intimate partnership. Having only one partner at any one time, whether for life or serial monogamy, contrasts with various forms of non-monogamy (e.g., polygamy or polyamory).

The term monogamy, derived from Greek for "one marriage," has multiple context-dependent meanings—genetic, sexual, social, and marital—each varying in interpretation across cultures and disciplines, making its definition complex and often debated. The term is typically used to describe the behavioral ecology and sexual selection of animal mating systems, referring to the state of having only one mate at any one given time. In a human cultural context, monogamy typically refers to the custom of two individuals, regardless of orientation, committing to a sexually exclusive relationship.

Monogamy in humans varies widely across cultures and definitions. While only a minority of societies are strictly monogamous, many practice serial monogamy or tolerate extramarital sex. Genetic monogamy is relatively unstudied and often contradicted by evidence of extrapair paternity. Monogamy in humans likely evolved through a combination of biological factors such as the need for paternal care and ecological pressures, alongside cultural developments like agriculture, property inheritance, and religious or societal norms promoting social stability.

Biologists distinguish between social, sexual, and genetic monogamy to reflect how animal pairings may involve cohabitation, sexual exclusivity, and reproductive fidelity in varying combinations, while serial monogamy describes successive exclusive relationships over time.

The word monogamy derives from the Greek μονός, monos ("one"), and γάμος, gamos ("marriage"), referring to the functional social behaviour of pair-bonding. The term can then be subsequently subclassified by context-dependent relational types. Generally, there are four intersecting definitions.

For instance, biologists, biological anthropologists, and behavioral ecologists often use monogamy in the sense of sexual, if not genetic (reproductive), exclusivity. When cultural or social anthropologists and other social scientists use the term monogamy, the meaning is social or marital monogamy.

Marital monogamy may be further distinguished between:

Defining monogamy across cultures can be difficult because of different cultural assumptions. Some societies believe that monogamy requires limiting sexual activity to a single partner for life. Others accept or endorse pre-marital sex prior to marriage. Some societies consider sex outside of marriage or "spouse swapping" to be socially acceptable. Some consider a relationship monogamous even if partners separate and move to a new monogamous relationship through death, divorce, or simple dissolution of the relationship, regardless of the length of the relationship (serial monogamy). The need to accurately define monogamy was highlighted in a 2012 work, which defined practices as either formal or informal polyandry. The researchers found 53 communities studied between 1912 and 2010 that practiced polyandry (in which women have multiple male partners). This broader definition indicated that polyandry was more common worldwide than previously believed.