Serial monogamy

Serial monogamy is characterized by a series of long- or short-term, exclusive sexual relationships entered into consecutively over the lifespan. In common usage partners need not be married, but there is never more than one partner at a time. This behavior is a variant of monogamy, in which a given individual has only one sexual partner throughout life. This behavior is sometimes referred to as a form of, or replacement for, polygamy. However, this practice inherently excludes the practice of having multiple simultaneous sexual partners.

Animals
Generally, any animals that do not mate with one partner for life can be considered serially monogamous, including those who find a second mate only upon the death of the first. There are arguments that evolutionary biology has selected a four-year mating cycle for humans based on natural birth spacing, as well as the belief that finding a 'fully' monogamous species is rare.

Western culture
Within Western culture, serial monogamy is considered more fundamental than "full" monogamy. Relatively few people consciously enter a long-term relationship wanting it to eventually end so as to begin another.

Divorce
Serial monogamy has always been closely linked to divorce practices. Whenever procedures for obtaining divorce have been simple and easy, serial monogamy has been found. As divorce has continued to become more accessible, more individuals have availed themselves of it, and many go on to remarry.