30-60% is not everyone. Of course infidelity is more common for people under 30 because younger people are better looking and hornier. The people who cheat accuse all others of doing the same so they don't feel guilty of their own transgressions.
Those percentages suggest a very large amount, especially considering since it's only accounting for married individuals, not even people that are currently dating in short/long-term relationship.
Again, it depends what you consider cheating. If your partner, say your partner is a woman for argument sake, confides in another man by telling him her problems and shortcomings at home and he consoles her with his words and pleasantries, some would consider that a form of infidelity, because she is given him what rightfully belongs to you (an ability to find resolution to home problems/an ability to make her happy during hard times). Again, the vast majority of people have played that game in their lifetime during some occasions. Then, there is the obvious forms of cheating involving sex and other physical interactions.
This is just my opinion based on what I have seen and experienced in my lifetime. I'm not saying I am right, I am simply stating what I believe.
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