As the question states, got curious and I was wondering if monogamy is an innate human behaviour or is it because of how we built society (religion, traditions, etc.)?
Let's say we go back in time, would we see humans settling down with a single partner at a time and caring for their children as a couple for life or would they reproduce with several leaving the mothers with their children?
Thanks!
Humans are believed to be mostly serial monogamists with a noticeable components of secret cheating. Serial monogamy means most will have a single partner at a time but will likely have several partners throughout their life, there is however an under current (~15%) of hidden cheating in most studied populations. Also I say mostly becasue human behavior is plastic and nearly every possible combination exists, albeit in small numbers. Males do have a stronger tendency to seek multiple partners at the same time, which makes biological sense.
like many social species you really have several mating strategies coexisting, often in the same head. Our large brains allow for more flexible approach to strategies.
In other animals exclusive (one mate forever) monogamy is exceptionally, almost breathtakingly rare, (not counting animals that only ever mate once). The Azara's night monkey is one of the few that has been backed by genetic research. Almost every monogamous species ever studied either has some rate of cheating, or is serial monogamous.
The easy answer is simply, no.
The longer answer is that it depends on whatever cultural norms that are practiced in a given area at a certain time.
Often powerful men in history had multiple lovers, but had arranged marriages. Like wise open relationships were very normal in the 60's and 70's of the 20th century. Also polygamous relationships are practiced in certain religions today.
While in modern times, especially in the west, we seem to tend toward the monogamous relationships, it seems to be more dependent on culture rather than biology.
I just read a book on the Evolution of Sex and one of the questions was why primates have lost the estrous cycle. The thought was that the sexual desire of the female anytime rather then periodically tends to keep the male "at Home" ensuring survival of the female and offspring. This implies that males are genetically engineered for monogamy but since females can survive now without a male (as opposed to those living in a cave) some males at least in younger years practice polygamy as do females.
No, they are not.
Polygyny, polyandry and group marriage are, or have been, practiced in various cultures. Polyamory and other forms of non-monogamy are practiced. There are estimates that four to five percent of Americans are involved in consensual non-monogamy (despite social pressure for monogamy).
A sizeable portion of what the porn industry is creating revolves around the subject of threesomes, group sex, cheating, cuckoldry etc. etc., so quite apparently there is a market for that. It turns people on, be that for the thrill of "breaking the taboo" or some underlying desire. (Excuse me for not posting a link to back this up. Use your favourite bookmark.)
There is nothing to indicate that non-monogamy in any of its forms is "unnatural" to humans. Tabooed in some cultures and / or religions, but not unnatural.
...over much of human prehistory, polygyny was the rule rather than the exception...
This paper puts that shift at about 18,000ya -- roughly the same time that agriculture became common, but much too recent to claim that Homo Sapiens as a species is now "naturally" monogamous.
It is rather something that developed culturally:
...an analysis of foragers in the Standard Cross-Cultural Sample reveals that male provisioning does affect the mating system. Societies with higher male contribution to subsistence are more monogamous.
On page 147 of "The myth of monogamy. Fidelity and infidelity in animals and people" (ISBN 0-7167-4004-4), David P. Barash concludes that about 80% of human societies lived polygynous before they came into contact with the "Western" culture.
