"And of course a large number of affairs, as documented by Dr. Harley and others, happen to even HAPPY marriages."
I totally don't buy it, and I've certainly never seen a case like that on these boards. Not one. There are plenty of cases in which the LBS creates a cloyingly idealistic view of the best M on earth while the WAS goes off the deep end as well, just in the opposite direction. But when people get back to a more objective place, I don't recall one case in which an LBS has said, "yeah, we did have a great M, the only big problem was the A."
Oldtimer,
I'm not a researcher, nor a counselor. I'm merely reporting what Dr. Harley and others have written, and I believe it. I do think it's a minority of marriages tho (maybe 20%?), and that the large majority of them do have problems, at best, or are dysfunctional, at worst, which leads to the conditions that make infidelity possible -- even probable.
I also think that these boards do not represent a scientific sample, and are highly skewed in that it's usually the betrayed spouse from whom we're hearing, and we're getting everything secondhand. I do see HUNDREDS of posts from LBSs that say "I thought we had a good marriage" . . . . "and he/she never complained before recently" . . . etc., and I'll ask the question "When did the marital complaints start?" and "Did he/she ever complain about 'controlling' behavior previously?" and -- INEVITABLY -- the answer I get back is that it ONLY started when the adultery did.
Sadly, in some social circles, infidelity has become not only ACCEPTABLE, but even FASHIONABLE. It's not always dysfunctional marriages that breed it, and I think we underestimate, in all of our "WHY did this happen?" angst, the sheer animal simplicity of "Because they were selfish, and it felt good, and having made the mistake, it became addictive."