Lots of nationalities have changed average height during my lifetime. E.g., nobody thought of Dutch as particularly tall when I was young. Today, young Sikh-Americans tend to be tallish. Nobody saw that coming either. Americans used to be stereotyped as lanky, but no longer. https://twitter.com/JJmarcone/status/1011476973691047938 …
My son's Sikh friend in high school shot up to about 6'6" (plus his new turban).