Alfred Sturtevant, one of the giants of genetics in the first half of the twentieth century, had first suggested tongue rolling as a Mendelian trait in 1940, a single allele bestowing the ability on its bearer or not. After the twin studies he, like a good scientist should, changed his mind, and said in 1965 that he was ‘embarrassed to see it listed in some current works as an established Mendelian case’. It is still taught in schools today.
