Cheating is the side effect of a set of inefficient rules that were created to specifically restrict human's nature ..

Seems to me that the same affliction is with people that lie, steal, and those that cheat....the thing that stands out to me, is that these people are trying to get something for nothing...."cheaters" want, what they haven't earned....they want to be able to keep, what they already have, and without paying the price, also have that, that they haven't really earned.....and I'm ranting again. Best of luck in your quest.

Robin Baker's Spear Wars gives you a clear answer: our evolution. Most of human evolution was before agriculture which changed everything. Sex was more random and the tight family not yet evolved. Using the latest camera technology, Dr. Baker studied what happens during coitus. He found that spermatozoa are specialized much like ants with only a small percentage able to fertilize an ovum. Most sperm gametes are soldiers, their job to guard the cervical os and ward off rival males. Dr. Baker concludes that men are serially monogamous.

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Two reasons...1) they are not entirely committed to the relationship, and....2) they think they can get away with it.

Quite honestly, it is highly doubtful that humans are naturally monogmous. humans are animals, with animal instincts. We often maek the mistake of thinking that becuse we are (sometimes) capable of rational thought that we are wholly rational, but we make many decisions daily based on emotion (instinct), than on rationality.

When two people commit to each other, even if they intend to be monogamous, every relationship goes throug peaks and valleys and sometimes even the best intentioned people whiel in a valley find their animal instincts (sex drive) take over and they stray. It doesnt' mean that he/she is a bad person, or tha they dont' love their chosen partner.

I think monogamy is a god ideal to strive for, but it is unrealistic to actually expect it over a lifetime, when only about 20-35%, depending on which study you reference are actually monogamous (as in being serially monogamous, one person at a time instead of one person period) over their lifetime. The concept of monogamy just is not compatible with human nature.

It would be healthier to have expecations mor ein line with human nature than to expect a partner to be exceptional.

My personal standard is that honesty is more important tome than monogamy. If i have a partner who "slips" I want to know about it. Secrets destroy more relationships than any other one thing. usually because you cant' keep secrets with someone who knows you well. They will find out and then the real betrayal will be the lie, nto the infidelity. Secrets only have power as long as they remain secrets. i doubt I'd have to really worry about an infidelity that my partner told me about. If he kept it secret, then yes, there is something to worry about.

It is easier to cheat and fulfill some sexual or emotional needs from another person than to breakup with one's partner and start fresh? So combination of fear and selfishness? They want to have their cake and eat it too. Have also never cheated.

Too many reasons, and probably some I haven't thought of.

They want out but don't have the guts to end it, so they put it on their partner's shoulders to take action.

Hormones!

But is it normal to cheat or does cheating mean the concept of one to one is not practicable from human's nature stand point

Usuakky because they can -

All of the previously named reason, but also revenge for being cheated on, for neglect, for abuse. There are so many reasons why people do the things they do.

Inability to communicate, lack of trust

They are in an unhealthy relationship and don't know how to end it. My first marriage of 16 years.

Boredom...lack of intimacy...thrills...grief...validity...