I think it's true. Most men want what they can't have. And once they have it, they want more.  I have observed enough in my travels to believe that this is true. If they could afford it, they'd have more than one wife and a boat load of kids. Of course the wife would have to take care of the kids, but he'd be the one searching for more wives!  Maybe some people can have nature socialized out of them, but that does not change the fact that men are polygamous by nature. The bigger question is why society and religion oppose nature on so many different levels! Could it be that humans have this irrational need to always be in control even though they never will be? 

Men are not the only ones who are polygamous. Perhaps you do not realize that there are also polyandrous societies on the planet, where one woman has several husbands.If you don´t want to live a monogamous lifestyle, you should be able to find people who, like you, prefer a polygamous lifestyle. I would also like to add that it is not true that all men cheat. My friend's father was the monogamous type. His second wife and his girlfriends all cheated on him, while he remained true to them although they did not deserve it.

The way I look at it is, biologically men are made to try and have as much sex as possible with as many women as possible. This is what has helped our species to survive and grow in large numbers.  

The problem with this sort of reasoning is that men are also programmed to defend their territory and their family at all costs. Yet, I am sure you would agree with me, that if you saw someone you didn't know standing on your lawn, it is hardly acceptable to attack him. Or if someone put their hand on your girlfriend's arm, it is hardly acceptable to attack them either.  

My point is, that like animals we have certain impulses. The thing that seperates us from the animals is that we have the ability to control these impulses or at the very least, avoid acting upon them. 

The Alpha males are. The other males would if they could but they have few opportunities because women select men with the best genes when having sex.  

It should be obvious that the total number of cheats for men and women are the same. A few men cheat a lot.Most women with Beta male mates will have sneaky sex with Alpha males when they are ovulating in order to select better genes for children. 

 Alpha males that did not spread their genes around are not our ancestors. Women that did not select the best genes for their children making their children the strongest and healthiest to increase their chance of surviving to adulthood are not our ancestors.