Polyamory is the idea or practice of having more than one loving intimate relationship at a time, with all partners knowing and consenting. It is practised by members of some intentional communities, and was and is one of the basic principles of a number of communes and communities, for example, ZEGG, the Centre for Experimental Culture Design, in Germany.
There are multiple reasons for practicing polyamory. They are:
1. Humility: When one's love partner has multiple love partners (oneself, plus one or more people other than oneself), then one does not dominate one's love partner(s), such that polyamory facilitates the virtue of humility in people who are in such a non-exclusive position. Therefore, one-sided polyamory (polygynous or polyandrous arrangements) only facilitates the humility of one of the genders, such that it is preferable that there be multiple people of each gender.
2. Eugenic breeding: Polyamory allows each individual to breed with more than one person, such that it allows a larger number of good gene combinations to be produced. There is a practical difficulty with arrangements of polyamorous reproduction though, which is the large number of children that are produced by any given nuclear family, due to the larger number of parents. The polyamorous parents must therefore pool their incomes together to purchase or build a dwelling that is large enough to hold all of the offspring.