It's the same with education. To the extent there is a racial correlation between these characteristics, racial discrimination in mate selection exaggerates the differences in the society's intelligence and income distribution. There would be greater equality if there weren't this kind of discrimination in mate selection.

In other words, if high-IQ people were forced to select low-IQ mates, high-income people forced to select low-income mates, and highly educated people forced to select lowly educated mates, there would be greater social equality. While there would be greater social equality, the divorce rate would soar since gross dissimilarities would make for conflict.

Common sense suggests that not all discrimination should be eliminated, so the question is, what kind of discrimination should be permitted? I'm guessing the answer depends on one's values for freedom of association, keeping in mind freedom of association implies freedom not to associate.