On Tuesday, I was at a presentation by two physicians who just returned from an 18 month stay in Lesotho. Lesotho has some of the highest HIV rates in the world (they estimate that 50% of the women under the age of 40 are HIV+) so naturally, sexual practices are a concern. Apparently, "concurrent monogamy" is the norm (as opposed to serial monogamy which is what is common here in the US). Many (most?) men go to South Africa for a period of time to work in the mines, leaving their wives behind. The men will have lovers while they are away, as will the wives who are back at home. You can see how this network of sexual partners can lead to skyrocketing HIV infection rates. The men also, apparently, have a very macho attitude about being men and absolutely refuse to wear condoms which also contributes to the problem.There are societies that quite openly tolerate cuckoldry. On the south sea islands with their small, closed populations, it is not uncommon that a passing stranger has sex with a local wife, and the resulting child being accepted into the family by the wife's husband. Expanding the genetic base of the population is always an evolutionary advantage.
D