it'd be interesting if someone studies what factors affect height over different races.
excluding genetics. what else.
one guess could be diet and nutrition. some countries have a wider consumption of milk. milk is famously linked with healthy bones. then you can correlate that with height.
another could be environment. if you equate Darwin's theories, maybe our ancestors didn't need to be bigger to gather food, or catch prey, or to survive. unlike a Giraffe where it had to grow its neck to eat from the taller trees.
maybe the trees have always been within reach in the asia pacific region. hehe