[barry-cotter]

Humans aren’t obligate monogamous but our level of sexual dimorphism is less than polygynous species like gorillas. Against this is the difference in upper strength where men are about twice as strong as women. Also in hunter gatherer societies we’re familiar with most men do not have multiple mates at one time and from the varying patterns of inheritance of Y chromosomes and mitochondria which are passed down solely along the male and female line respectively ~40% of men leave descendants. That’s not compatible with polygyny. Humans are not obligately monogamous or polygynous but all evidence points to more of the first than the second.

[amanaplanacanal]

From what I can tell, hunter-gather societies, and possibly all of our pre-agriculture ancestors, are serially monogamous with some fooling around on the side. Children probably received support from the whole band or tribe.

The sexual part seems pretty familiar from looking around current society, and the children support part isn't far off from now either.

[danielcarver]

This makes absolutely zero sense. Not only is a figure of 40% male reproduction compatible with polygyny, it is solely compatible with polygyny.

If humans were monogamous as you suggest, the figure of male reproduction would be far closer to 100%. But we’re not. We’re polygynous — a harem-based species. And the 40% figure you just cited proves that: Less than half of the men mate with all of the women. That’s not called monogamy dude. That is called polygyny.