I think these are generally reasonable, but that the prevalence of polygamous societies is an indication that the first point is significantly culturally influenced, e.g. Wikipedia:
Worldwide, different societies variously encourage, accept or outlaw polygamy. In societies which allow or tolerate polygamy, polygyny is the accepted form in the vast majority of cases. According to the Ethnographic Atlas Codebook, of 1,231 societies noted between from 1960 to 1980, 588 had frequent polygyny, 453 had occasional polygyny, 186 were monogamous, and 4 had polyandry[5] – although more recent research found some form of polyandry in 53 communities, which is more common than previously thought.[6] In cultures which practice polygamy, its prevalence among that population often correlates with social class and socioeconomic status.[7] Polygamy (taking the form of polygyny) is most common in a region known as the “polygamy belt” in West Africa and Central Africa, with the countries estimated to have the highest polygamy prevalence in the world being Burkina Faso, Mali, Gambia, Niger and Nigeria.[8]
I think these are generally reasonable, but that the prevalence of polygamous societies is an indication that the first point is significantly culturally influenced, e.g. Wikipedia: