When you ask psychologists, biologists, and sexuality experts whether humans are meant to be monogamous, the first thing they will come back with is, What do you mean by “meant to be”? Society, culture, and religion affect what we do as much as evolution and biology. So they were asked if monogamy is "natural" for humans. Author and educational consultant Dr. Elisabeth Sheff begins with the facts that most of the experts quoted agree upon.
I'm not sure if there is any intention behind it, but monogamy certainly is not "natural" in that it does not seem to be effortless for anyone. Things that are "natural" for people—like breathing, blinking, and wanting to protect our children—do not need nearly so many social strictures to keep them in place. Monogamy, or any form of sexual exclusivity, however, has many rules and laws governing it.
Rather than the naturalness of monogamy, the fact that cultures around the world and across time have created hundreds or thousands of protocols and punishments to patrol and enforce sexual exclusivity (especially for women) indicates that it is socially constructed and not something humans will do "naturally" without external intervention. If humans didn't crave a variety of sexual experiences with new partners, then cultures would not have to work so hard to keep people from having sex with someone who is not their spouse.
While the experts agree about humanity’s natural urges, some go on to say that monogamy, while unnatural, is not necessarily a bad thing, nor is it unachievable for individuals. However, it is not universally enforceable. People have tried so many other types of relationships: polygamy, serial monogamy, public fidelity with private infidelity, etc. and they all have their drawbacks. So human beings will continue to struggle with the desire for a loyal lifelong soulmate vs. the desire for sexual variety. Read what five different experts have to say on the subject at Hopes and Fears. -via Digg