Cultural cartography Inbreeding population of the world April 21, 2015 Alex Inbreeding occurs when cultural factors dictate marriage or when a population is relatively small and quite isolated. The largest amount of inbreeding has Muslim countries of Northern Africa and the Middle East. Related Posts:Legal Marriage Age for Girls by CountryBirths Outside Marriage in Europe: Trends, Changes,…Marriage in the US: Where the most people are married?Youngest Marriage Age Allowed in the U.S.Which countries get the most paid vacation days?Average Age of First Marriage by Country MappedCousin Marriage Around the WorldWorld Muslim Population