Monogamy
The idea of monogamy is often debated as a biological impossibility. The argument is not settled on that front.
But science was not one of the reasons European colonizers insisted Africans had to be monogamous. The reasons range from the religious to the political and to the economic.
Kevin MacDonald notes in “The Establishment and Maintenance of Socially Imposed Monogamy in Western Europe” that enforced monogamy in medieval Europe was mainly a method of social control over women and lower-class men.
Men of privileged birth did not tend to be bound by these rules even if they do not wed all their women-lovers.
Monogamy, therefore, can be seen in the same light as we see other things Europeans bequeathed to Africans – arrogant arbitrariness.