alt Hacker NewsWe know that people with red hair tend to metabolize anesthesia differently. It is not completely implausible that there is also a correlation between looks and other traits, although it seems almost impossible to me to untangle cultural, environmental and genetic effects.
Of course, any two traits can be correlated. But unless there is an obvious causal mechanism ("whiter skinned people get sun burns more easily", "darker skinned people tend to have vitamin D deficiencies at higher latitudes"), there's no reason to assume it and start looking for it to prove or disprove. It's a priori just as likely that there is a genetic link between toe shape and intelligence as skin color and intelligence. Yet no one is doing the science of measuring toe length correlation to intelligence, just skin color ("race").