I think in our current society most of us breed just fine, or at least have the strong desire to do so. Whether we do well at childrearing (not the same as overall fertility, of course) is another question.
You could do a case study of a single nation. I personally think that coming up with an operational definition may be the insurmountable issue. A USMC Private and Bill Clinton both can probably be put into the alpha male category, for example.
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