Men will either dislike it or seek it out. So what they end up with is what they were attracted to in the first place.

But I think it's a sweeping generalisation to say that women become single mothers because they're too smart for their men. If they were too smart, perhaps not marrying that man might have been a clever thing to do in the first place. This is from someone who was married twice btw.

I also think women GET gutsy when they're doing it alone. I know I've learnt far more independence from being a single mum than I did from being married. So I think single mums will seem more capable a lot of the time, but this may not necessarily be a factor in the decline of the relationship.

I also personally think relationship breakdowns are a lot more complex than that, and contain many many layers of anger and resentment about a lot of things, and while this may be one thing, I certainly doubt it's the main thing.