Hello Herostratos,
What is 'uncivilized' about polygamy?

As for your question about why polygyny is allowed and not polyandry, there are numerous reasons. First of all, if every person in the relationship wishes to have a child, this is possible in a polygynous relationship as each wife has her child, but it is not possible in a polyandrous relationship as there is only one person giving birth, thus putting all the burden on one individual, which is unfair. A man can spend equal intervals of time with each wife, while a woman would not be able to from pregnancy. At some point humans must acknowledge that men and women are different and they have different bodies, so while one arrangement may work out for men, it may not necessarily work out for women.

Does this answer your question?