the simplest reason is there are more inter racial marriages.
Chinese are marrying other races, Indians, Malays and Caucasians to
produce a better looking generation. Face it, its more beautiful to
have a sharp nose, double eye-lids, deep-set eyes, with sharp
features.
Also, presenting well - "beautifies" themselves. When one is born
to different racial parents. You would not see the usual traits of
the Chinese, kiasuism, eating, slurping noodles loudly, Q-ing up
for Hello Kitty, and speaking Singlish. Having shallow knowledge of
global issues and shallow sense of humour. Will not be inclined
towards reading good novels and the arts. Would rather watch Mr
Bean than Goodness Gracious Me.