.they were in a relationship, spending lots of resources raising the kids, or not. In Asian cultures, there was a lower instance of extra-marital copulation, for whatever reason, thus the need to develop males with all that unnecessary testosterone and size never evolved. So, European males in general have more testosterone than Asian males, but Asian women are just like other women and still attracted to guys with facial features that say "look at me! I have testosterone!"...probably at least in part because their male children will get the "more testosterone" genes and thus may have more children because they in turn will be more attractive to females in general.

Sorry, Asian males. It's really not your fault. To cheer you up a little, I can tell you that most studies do find that people find people from their own groups the most attractive in general. And cultural similarities (or barriers) sometimes make a lot of difference.

On the bright side for Asian women, the evolutionary path that made Asian males less attractive makes Asian women more attractive. They are smaller, with more "feminine" features than European females, such as bigger eyes, smaller chin, smaller mouth, smaller nose--basically, they look more like infants.

So there's the reason in a nutshell! For a funny take on this from some college kids, look up "Yellow Fever" on youtube