If you observe Chinese, Korean and Japanese men you’ll notice that they don’t tend to grow very much facial hair or body hair. The same is true for Native Americans who are cloely related to Far Eastern people. Native Americans don’t tend to grow any facial or body hair and they rarely lose their hair on their heads.
Facial and body hair growth are triggered by an increase in the androgen hormone dihydrotestosterone (DHT). DHT is also the hormone that causes scalp hair loss.
Middle Eastern and Indian men tend to have a lot of facial and body hair and so do European men with dark hair. These types of men are the ones that experience the most hair loss.
In every data set there are outliers. That means some Chinese men who don’t grow any facial hair still lose their scalp hair, but they are anomolous. The majority of people follow the predictable trends.
Androgen and stress hormones are the most significant root causes of hair loss. There are other reasons, which are built into the genes and develop as people age, but when looking at broad patterns amoung humans, the androgen and stress hormones are the two biggest causal factors.
So, why don’t Chinese people lose their hair? The answer is the same reason they don’t grow beards or body hair — they produce less of the androgen hormone DHT, which is the hormone that causes beard growth and hair loss.