I'd say that the lack of morals ometer leans much more in the direction of the intelligent than the unintelligent. But its pretty complicated stuff, you have evil born of ignorance and lack of education and then evil born of power and knowing more than whoever is being exploited. And that's just to start
I think moral lapses are universal. Let's not forget that to millions (billions?) of other people worldwide WE'RE part of the richest class enjoying our luxuries while they starve. And I don't think about that for more than a few seconds, most days.
Morality is about empathy, isn't it, and there are so many ways we can have empathy blunted or cut off. Comparatively the percentage of people who can turn it off face to face and violently attack someone is pretty low. Intelligence might have something to do with this capacity, but I doubt there's a direct link. Success (financial, political, etc.) may very well be linked to capacity to shut off empathy.
Pinker argues that peoples circle of empathy has expanded with education - most of us naturally feel it for our family and friends and need to make an effort to feel it for people on the other side of the world (though there are techniques to bridge that gap, e.g. Oxfam adverts on TV.)