That said, all of the science on the subject is measuring very specific things and should be interpreted narrowly. You can say income is broadly correlated with fertility, and rule out some specific measures of education as an explanation for that particular (small) piece of the variance pie, but you can't then just make up an explanation and pretend it's supported by science. Just-so stories like the one you're telling are at best food for thought, or fodder for future experimental hypotheses. There's no scientific basis that I know of for the kind of mechanism you're proposing. Though I'd be happy to see more studies on the subject.
That said, all of the science on the subject is measuring very specific things and should be interpreted narrowly. You can say income is broadly correlated with fertility, and rule out some specific measures of education as an explanation for that particular (small) piece of the variance pie, but you can't then just make up an explanation and pretend it's supported by science. Just-so stories like the one you're telling are at best food for thought, or fodder for future experimental hypotheses. There's no scientific basis that I know of for the kind of mechanism you're proposing. Though I'd be happy to see more studies on the subject.