Monogamy is useful in some ways, as the other commenters have mentioned. Being useful does not mean monogamy is destiny, or that we are "meant" to be any one thing. That said, I'd be cautious about open relationships. More individuals might stabilize the arrangement, but it very much depends on who is involved.

Monogamy is best for me. If you are with the right person, it is easy.

yes

Either that or someone is eventually going to get a machine gun and take out the competition

It's a different type of love,to me a more intense type of love that calls for such an intimate intertwining of personalities and individual selves which calls for a more or less singular commitment to one another.

No, that's a social construct. I've thought about having an open relationship and in a sense I'm already in one. My BFF who I dated 15 years ago is still a huge part of my life but we haven't been sexual partners since we stopped dating. She meets my intellectual needs. She says we are in a sexless open marriage. My BFF isn't currently in a relationship but I am. My GF, BFF, and I spent Thanksgiving together. My GF likes to cook and cooked for us. My BFF brought booze and desserts. I hosted and cleaned up.

Anyway, one person is unlikely to meet all of your needs, especially over multiple decades. If you find one - yay for you!

One of my undergrad psych professors postulated that monogamy was a practical construct allowing for managing the household, caring for children, and so on. It was fine when we only lived to be 30-40. Now, with much longer lifespans, monogamy is unrealistic. Serial monogamy or open relationships might now be the way to go.

For me, I don't know if I could deal with sexual non-monogamy. Maybe if the third person was female? Triad relationships often have one person as the odd person out which sucks for that person. That shifts over time and is a point of vulnerability of a triad as is jealousy. More than 3 is just too complex for my taste.

There Is no yes or no answer to this question, it depends entirely on the two individuals involved agreeing to either exclusivity or not. Then the problem only arises if one of the partners changes their mind after vowing fidelity at the start. If both individuals understand and agree that they are open to having other partners, then there should be no problem, theoretically. I say theoretically, because in practice human nature comes into play and emotional attachment. This can lead to feelings of jealousy and resentment, even when it has been agreed that an open relationship is what both parties want. We can feel very proprietorial about our partners, even when we want to have other partners ourselves....it can lead to feelings of resentment and jealousy, irrational though that may be. Women need to feel security if children are brought into the equation, so quite often the woman is the one who changes her mind about the open nature of the relationship. Relationships are complicated and are much more than just being sexually compatible, I know of many long term monogamous couples, some who sleep separately, but still seem to have happy and functioning relationships. No one size fits all when it comes to this question would be my conclusion.

When these rules were invented, people only lived to 30 years. Now people live to 90 its only natural couples outgrow each other

No I don't think we're meant to be monogamous, biologically speaking we're better off spreading our DNA to multiple partners. This in turn weeds out the weak and builds the strongest gene pool.

What humans are meant for and what they can and should strive for IMO are very different. We're not meant to fly but we do that pretty often and for good reason. I'd rather have one person that I know I can trust and rely on in this life. We're not meant to watch TV or drive cars but for some reason when it comes to monogamy everyone wants to follow strict basic biology.

Monogamy is hard, but I haven't found anything in this life worthwhile that isn't so why should it be?

Apparently donotbelieve has blocked me (?), so i cannot review its remarks. (My words must be so hurtful to the extra-sensitive.)

Monogamous::: this term usually is used in conjunction with "sex" and nothing else.

But, i think the expectation of sexual exclusivity is equally cultural and genetic.

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Esther Perel has some great insight about these issues: "The State of Affairs" is a very important, and interesting book. The concept of total commitment to a marriage is a very recent concept. And it is not working.

We all need romance, and mutual non-sex relationships, and sexual encounters, regularly. And that often requires strangers becoming new friends.

But, being all-in for only one other human being for decades will create significant brain deformation, and consequently, regret, disappointment, and despair, of all the could-have-beens.

Perel explores the FACT that many many happily married people engage in fun with others. The marriage is great. But, it is not possible for that one person to satisfy all human needs.

An introduction to her thoughts:

Natural selection gave us jealousy to encourage couples to stay together long enough to nurture their young. And sure enough, jealousy is cited as the main challenge in polyamorous relationships. This doesn't mean I think open relationships are bad because they're counterintuitive. It's counterintuitive for most folks not to afford belief to deities, or engage in confirmation bias or agency inference, or to be not very self-aware, and on and on. We attain the so-called Great Virtues by working against many of our defaults, by making sacrifices and doing things we'd rather not do, all things being equal.

However ... since I personally find the finer points of monogamy counterintuitive enough, I have no interest in further complicating the matter, either.

The ideology behind monogamy was born from the practice of marriage being a business as well as a political tool.

If you were a provider of goods and services way way way back in the day and your wife had only bore daughters whom of which weren’t allowed to be taught a trade or run a business. ( and to listen to some people you’d swear that it’s still like that smh )
And if you wanted have a time when you could stop working you would let your sons run things and their wives would take care of you along with your wife.

And if you only had daughters well you’d have to work until you died. But someone apparently was offered money for the exclusive right to marry their daughter and ding ding yes but it will cost you.

So then if you had a daughter you also had a source of financial security and you could also broker business deals, end wars, create political alliances and y’all get the picture.

And when consider that there’s still parts of the world where arranged marriages with dowries involved the practice still serves it intended purpose.

But as far as the rest of the world goes you could propose ending monogamous relationships but you might want to consider that the rules for child support might swing in favor of the men involved due to the Maury Povich effect would greatly increase.
That’s just my take on it.

I’d say in evolutionary terms that it’s the best strategy for raising the next generation. Psychology and social studies have found this to be true as well. But the desire for sexual variety is still in the genetic makeup of humans, particularly men, and I think casual sex amongst multiple partners is still possible even when in a committed relationship or in a marriage! Thoughts?

Humans aren't "meant" to be anything. We're just here, we are conscious. As such, we make our own choices. Some of us choose to be monogamous (for many reasons, including unhealthy societal expectation), some of us choose "open" relationships or polyamory. I feel people can do whatever they want so long as they are not committing force, fraud or coercion against anyone else. In romantic-love relationships, I think it's hard to make polyamory work unless everyone involved is very mature and don't become jealous. I know there are examples of monogamous couples who claim to have been happily married for longer than I've been alive (I'm 57). I guess what I'm saying is that it's all good. People should seek happiness in whatever way works best for them (abiding by the rules I previously mentioned here.). Ok, shuttin' up now.

Teachers, parents and the like are not intimate relationships. There are some it works for and I’m happy for them and accept it. It’s not my cup of tea.

Nope.