Is monogamy societal?

I don't know. Some animals believe it.... that much I know. It's also instinctual for a lot of them.

People always have a choice. The problem is that in our anti-traditionalist society, monogamy works against all our "modern" values. It's only one reason why more traditional cultures...look down on us!

I think both. We all do long for a partner. That's why we have best friends and romantic partners. That's why people don't like to eat alone, sleep alone, or generally be seen in public alone. And yet we are not monogamous. We may have several best friends or several romantic partners at either the same time or at different times of our lives.

At the same time, society puts a chokehold on us to be manogamous. I don't necessarily believe in it, yet I'm not going to change it. I'll try to live by it, because I'm told that makes a good marriage. But my body says my true nature is not monoagmous. I still have crushes, men still catch my eye, and I still lust after celebrities.

So yes, monogamy is societal, and we all do long for a partner.

I couldn't have said it better Squigglefish,,,you hit the nail on the head

It is a new command for this Age of human maturity? How equality of people can exist in polygamy?

It is for some species however for humans it was created that way! CREATED! It is not necessarily a instinctual male reaction! It was needed to maintain some control over the species! Actually through religion and believe it or not women that could dominated were able to restrain males from seeking various partners! religion made it a "Sin" so a male would be riddled with guilt for lack of fidelity! It's all about control! This will of course not be a popular answer and that is expected because that is the result of the way it was created! religious beliefs will recite from the bible scriptures! That is fine however, who do we have as witnesses of those writings or should I say statements! It's all about "Faith" for them. Anyhow. study the different stages of Man (Women) and eventually you will see the patterns as they are developed (Evolved) of billions of years!!! Why do many men cheat? Why do many men cheat and state that they still love their spouse but just feel the need to step out once in a while? It is so common that it has been going on for centuries and now at a rate of 78% with women now included! Now That's evolution!

Yes--sort of. Biologically, we would not be classified as monogamous (like gibbons) nor promiscuous (chimps). It would be more accurate to classify us as serial monogamists; we are monogamous for periods of time (relationships) with multiple partners throughout life, generally speaking. Several theories posit that relationships tend to last less than 6 years-- because biologically, that's all the time a couple needs to conceive, birth, and raise a child past infancy, ensuring its survival.
It's advantageous for both sexes to be somewhat monogamous for a few years so that: 1) Men can ensure paternity, avoid cuckholding 2) Men can protect their genetic investment (child) who is especially helpless 3) Women can thus have help in raising child, securing food, protection until the child is past toddlerhood and more likely to survive 3) Human female ovulation is concealed, so she is constantly sexually receptive--meaning that numerous copulations will occur (bonding) and it's a good idea for the guy to stick around to make sure he's the impregnator, not the guy in the next cave.

Insofar as life-long marriages are concerned--yes, that is a construct of society and has no advantages biologically. Yes, I'm a geek.

yes, i do think it is societal.
society as it exists today undermines the human being's natural inclination to connect meaningfully with others while at the same time glorifying monogamy (not that monogamy is a bad thing but i do think it is glorified out of proportion). so therefore people run around brainwashed, looking for "the one person who can complete them" etc, etc, because the importance of a whole variety of social needs has been funneled into this one single relationship.
that's how i explain it roughly, anyway.