I think cultural heitgare has an influence here if you look at classical depictions of (female) beauty, in China, Japan, etc, the ceramic-like white skin factor seems a definite beauty standard . I am not sure when having a tan the darker the better became a beauty symbol in Western countries, among Caucasians, I haven't explored the cultural roots of that particular standard but I do remember that as a teenager I definitely didn't appeal to the girls during and after the summer vacations, when their eyes became soft and soft and softer by the reflection within them of those boys whose parents had taken them for a 6-week vacation at Mediterranean beaches