Look its easy to tell. If you live/orginate in north america you can tell if someone is from texas or jersey. If you live/originate in Europe you can tell if someone is Irish, Welsh, French, German. If you originate/live in asia you can tell whether they are Afghan, Indian, Chinese, Korean, Japanese, Bangladeshi etc. It becomes really easy when you get used to it. Those people that can't tell the difference really havent seen much of the world people that can will know that different races etc have different skin colour tones, face complexion, height etc. For instance South Indians are shorter than North Indians and speak different languages however common indian tongue is of course Hindi.