Polygamy in Africa: concentration, context, and caution

In Pew’s 2010-2018 comparative household data, a strong regional gap appears: about 2% globally live in polygamous households, versus 11% in sub-Saharan Africa. Within Africa, the highest values in this comparison cluster in a West and Central belt, including Burkina Faso (36%), Mali (34%), and Nigeria (28%), while others in the same set are much lower, such as D.R. Congo (2%).^[1] This entry treats that gap as the main question, then tests how legal structure changes the reading.^[4] It also checks whether additional demographic context supports a single explanation.^[5]

Scope note: why this entry uses a 15-country comparative slice

This piece is intentionally built around the high-prevalence country list shown in Pew’s published figure.^[1] It then adds legal context from a separate source.^[4] It also adds demographic context from OWID.^[5] This keeps the evidence in one consistent frame from start to finish.

The tradeoff is scope. A 15-country slice is excellent for showing concentration and contrast at the high end, but it is not a full continental distribution. It should be read as a focused comparative window, not a census of all African countries and not a time-series trend test.

What this entry answers

• Where polygamous-household prevalence is highest in Pew’s 2010-2018 African comparison data.
• Whether the pattern is continental or regionally concentrated.
• How internal spread, including the low-end D.R. Congo outlier, changes the concentration reading.
• How legal status differs across high-prevalence countries, including civil-customary duality.
• What demographic and historical research can plausibly explain, and what it cannot.

Short takeaway

The strongest pattern is concentration, not universality. In this 2010-2018 comparison, the highest measured prevalence values are clustered in West and Central Africa, but countries in that same high-prevalence set do not share one legal model or one demographic profile.^[1] The legal layer is mixed.^[4] The historical layer points to persistence under long-run disruption.^[6]

Where prevalence is highest in the 2010-2018 comparison dataset

Pew’s global short-read, based on census and survey sources from 2010-2018, reports that only about 2% of the world population lives in polygamous households, while sub-Saharan Africa averages 11%. The same source shows a much higher cluster among selected African countries, with Burkina Faso at 36%, Mali at 34%, and Nigeria at 28%.^[1]

In the transcribed country set used here (15 countries shown in the Pew figure), values range from 36% to 2%, with a top-ten average of 26.1%. This is not a marginal difference from the global baseline. It is a distinct concentration that deserves a specific regional reading rather than an “Africa as one unit” interpretation.

Key figures

High-prevalence country profile

Values are transcribed from the published chart labels in Pew's 2020 short-read.

So what this means

The high values are real, but they are regionally concentrated. The right question is not “Is this African?” but “Where, and under what social conditions, is it prevalent?”

In Pew’s 2010-2018 comparison, the highest polygamous-household shares are concentrated in a West and Central African cluster. This is a focused high-prevalence list, not a claim about all African countries.

Concentration is regional, not continental

Country boundaries are from Natural Earth. Hover or tap highlighted countries to view data. Blue highlights West Africa (11 countries) and green highlights Central Africa (4 countries) in this 15-country set.

In this entry’s 15-country comparison set, 11 countries are in West Africa and 4 are in Central Africa. None of the high-prevalence countries in this list are in Southern Africa. None are in North Africa. East Africa is absent from this high-prevalence set as transcribed from the Pew figure.^[1]

That does not mean polygamous households do not exist in those other regions. It means they do not appear in the highest-prevalence group shown in the Pew comparison chart. This distinction matters, especially for public communication.

Internal spread: West Africa vs Central Africa

Reading the country list in two groups improves clarity.

The West Africa group in this set includes 11 countries, and averages 24.36% in the transcribed values. The Central Africa group includes 4 countries, and averages 9.5%.^[1] This does not mean Central Africa has low prevalence everywhere. It means the specific countries shown in this Pew comparison chart produce a lower average than the West African cluster in the same list.

The difference also appears in range structure. In West Africa, values run from 10% to 36%. In the Central African countries included here, values run from 2% to 15%.^[1] So the two groups differ both in central tendency and in upper tail.

The D.R. Congo value at 2% is important here. It sits in the same West/Central comparison frame but is 34 points below Burkina Faso, so the pattern is best described as concentration with large internal spread, not a uniform regional block.^[1]

One practical benefit of this split is communication discipline. Without it, “Africa has high polygamy” becomes a vague statement that hides where the concentration actually sits. With it, the statement becomes more useful and more accurate: “In this cross-country comparison, the highest values are concentrated in a West African cluster, with lower values in the Central African countries shown.”

This kind of reframing does not weaken the evidence. It strengthens it, because it preserves the strongest pattern in the data while removing unnecessary overreach.

Legal status is mixed, even inside high-prevalence countries

The next layer is legal structure. The data does not show one legal model across high-prevalence countries. WPR’s 2026 legal-status table places some high-prevalence countries in a fully legal category, others in “legal with restrictions” or “legal for Muslims only,” and others in “customary law” or “illegal but socially accepted” categories.^[4]

This is where legal duality matters. A country can prohibit polygamy in civil law and still permit or tolerate it through customary or religious channels. In WPR’s African examples, Liberia, Malawi, and Sierra Leone are explicitly categorized as “permitted by customary law, not legally recognized,” alongside countries such as Ghana, Niger, and Nigeria in the same category label.^[4] Within the 15-country prevalence slice used in this entry, this dual category includes Niger and Nigeria. Liberia, Malawi, and Sierra Leone are outside this prevalence slice but sit in the same legal label in WPR, which shows the category is broader than the Pew comparison set.^[4]

Legal categories among the high-prevalence countries

This chart counts legal categories for the same 15 countries shown in the prevalence chart.

So what this means

High prevalence does not imply one uniform legal regime. Legal design, recognition, and enforcement are part of the story, and they differ across countries in the same prevalence group.

A practical implication follows. Comparative prevalence should not be interpreted as evidence that one policy instrument will produce the same effect everywhere. Legal pathways differ, and those differences shape both reporting and lived outcomes.

Gender-ratio context is plausible, but mixed in this cross-section

Pew notes that polygamy is most common in places where people, and particularly men, tend to die young.^[1] That is a plausible mechanism and it aligns with long-run demographic arguments in the literature. But the country cross-section in this comparison set is not cleanly one-directional when measured with one indicator.

Using OWID’s latest available “sex ratio by age” values for 30-year-olds (male per 100 female) across the same 15-country set, most countries are below or near parity, but not all. Niger, Nigeria, Mali, and Togo are above 102, while several peers are below 100 and one outlier is much lower.^[5]

Age-30 sex ratio in the same 15-country set

A value of 100 means parity (100 men per 100 women). This chart is descriptive context, not a causal test.

So what this means

A demographic mechanism is plausible, but likely operates at broader population or historical scales rather than as a one-indicator country-by-country rule in this cross-section.

This is where many analyses become overstated. The numbers above provide context, but they do not by themselves identify a causal chain from sex ratio to household form in this comparison set, country by country. That is why the next section moves to long-run historical evidence instead of forcing a single-variable explanation from this chart.

What the historical literature adds

The historical evidence is stronger than a simple cross-sectional story, but it is still about correlation and long-run adaptation rather than deterministic fate. Recent work by Lowes, Nunn, Robinson, and Weigel links slave-trade exposure to durable social-structure outcomes, and discusses polygyny as one of the social responses studied in related literature.^[6]

Their paper also points directly to Dalton and Leung’s work on why polygyny is more prevalent in Western Africa from a slave-trade perspective.^[7] The mechanism in that literature is not framed as cultural exceptionalism. It is framed as institutional adaptation under severe demographic and social disruption over long periods.

That framing matters. It keeps interpretation anchored in testable historical processes rather than moral ranking or civilizational claims. It also aligns with the core empirical pattern in this comparison dataset, which is spatial concentration and legal heterogeneity.

Interpretation

Taken together, the evidence supports a layered interpretation rather than a single-cause story.

First, prevalence is concentrated in a specific West and Central African comparison corridor, but with substantial internal dispersion, including the D.R. Congo low-end outlier. Second, legal architecture is heterogeneous even within that same corridor, and civil-customary duality is part of the observed structure. Third, demographic context is directionally plausible, but the cleaner explanatory signal in this entry comes from long-run historical work, not from one contemporary cross-section alone.

This combined reading supports comparative clarity without overclaiming causality. It does not support treating all African regions as one profile, reducing differences to one demographic indicator, or assuming one legal reform template will travel cleanly across contexts.

What this means for non-specialist readers

1. The headline pattern is real: high prevalence is concentrated in a specific West and Central African corridor.
2. The second pattern is equally important: legal status is mixed, including civil-customary duality in several countries.
3. The third pattern is interpretive: demographic context and historical research provide plausible mechanisms, but none of these sources justifies a one-cause claim.

If the goal is public understanding, this is the most honest summary: in this comparison dataset, where prevalence is high, the pattern is strong enough to measure clearly; why it is high is multi-layered and requires legal, demographic, and historical context read together.

Limitations

• Pew country percentages here are transcribed from chart labels in the short-read figure rather than from a separate downloadable country table in the same page.
• The analysis uses a high-prevalence comparison subset and therefore is not a full distribution across all African countries.
• This entry does not estimate how country-level prevalence changed after the 2010-2018 source window.
• World Population Review legal categories are secondary summaries and may simplify legal practice, enforcement, and subnational variation.
• OWID sex-ratio values provide demographic context only, and do not identify causal effects on household forms.
• Historical slave-trade studies identify long-run associations under specific model assumptions, which should not be read as deterministic predictions for current policy.

Sources

References

1. Pew Research Center. Polygamy is rare around the world and mostly confined to a few regions (Short Read, December 7, 2020; updated April 14, 2024). https://www.pewresearch.org/short-reads/2020/12/07/polygamy-is-rare-around-the-world-and-mostly-confined-to-a-few-regions/
2. Pew Research Center. Religion and Living Arrangements Around the World (December 12, 2019). https://www.pewresearch.org/religion/2019/12/12/religion-and-living-arrangements-around-the-world/
3. Pew Research Center. Appendix A: Methodology (Religion and Living Arrangements Around the World). https://www.pewresearch.org/religion/2019/12/12/appendix-a-methodology-11/
4. World Population Review. Countries Where Polygamy Is Legal 2026. https://worldpopulationreview.com/country-rankings/countries-where-polygamy-is-legal
5. Our World in Data. Sex ratio by age (grapher dataset). https://ourworldindata.org/grapher/sex-ratio-by-age.csv
6. Lowes, S., Nunn, N., Robinson, J. A., and Weigel, J. L. (2024). The historical origins of the matrilineal belt. Philosophical Transactions of the Royal Society B, 379(1897). https://pmc.ncbi.nlm.nih.gov/articles/PMC10799733/
7. Dalton, J. T., and Leung, T. C. (2014). Why is polygyny more prevalent in western Africa? An African slave trade perspective. Economic Development and Cultural Change, 62(4), 599-632. https://doi.org/10.1086/676531
8. OECD SWAC. Polygamy remains common in West Africa. http://www.oecd.org/swac/maps/77-polygamy-remains%20common-West-Africa.pdf