A global map of traditional monogamy and polygamy

The world map of traditional monogamy and polygamy

A curious ethnographic map divides the planet according to historical marriage practices, before globalization and modern laws partly homogenized the models. The legend distinguishes six categories, from strict monogamy to polygamy with or without cohabitation.

The red tonalidad, which dominates Europe, East Asia and Southeast Asia, marks the regions of strict monogamy: exclusive unions between one man and one woman, with no social tolerance for second wives. The blue, which extends across much of the Muslim world and South Asia, describes a situation of monogamy with polygyny allowed as an exception (not as the norm). The green and purple tones are concentrated in Oceania and North America, where polygyny occurred between sisters who cohabited or lived separately. The orange and yellow, in Africa, cover cases of polygamy with or without cohabitation between wives who were not related.

Why was polygamy more common in some regions than in others?

The historical determinants are varied: from the agricultural economy that needed more labor (more wives = more children = more hands) to kinship structures and religion. In societies with high male mortality from wars, polygyny acted as a reproductive insurance policy. Today, however, most of those countries have formally adopted legal monogamy, even though the practice persists informally in rural areas.

Some analysts point out that strict monogamy correlates with greater economic development, but it is unclear whether this is cause or effect. The occasional Mormon example — a group that abandoned polygamy more than a century ago — shows that a community can prosper after the change. On the other hand, it is argued that polygamy tends to concentrate women among a few rich men, creating a surplus of young unpaired males that can destabilize social cohesion, but the debate is inconclusive.

In any case, the traditional map is a vestige of premodern realities that globalization and equality laws have been eroding. The curious reader will find in specialized discussions the demographic calculations and anthropological analyses that break down each tonalidad.