Why do very unattractive workers earn so much?

Kanazawa and Still (2018) showed that very unattractive workers earned more than unattractive workers, sometimes more than average-looking or attractive workers, because they had higher levels of intelligence and education, but they did not explain why very unattractive workers had higher intelligence and education. There are both theoretical and empirical reasons to expect that some intelligent men may prefer to marry very unattractive women. The analysis of the National Longitudinal Study of Adolescent Health (Add Health) shows that very unattractive women were significantly more likely to be married at Age 29 than unattractive or average-looking women, and their spouses or partners earned significantly more than those of unattractive or average-looking women. If intelligent men have historically preferred to marry very unattractive women generation after generation, then, because both general intelligence and physical attractiveness are highly heritable, this can explain why very unattractive workers are more intelligent and achieve higher education, thereby earning more. It can also explain why the positive correlation between intelligence and physical attractiveness is not larger despite assortative mating of intelligent men of higher status and physically attractive women over many generations.