No evidence for a genetic basis of tongue rolling or hand clasping.
D005260:Female; D007839:Functional Laterality; D005826:Genetics, Medical; D006801:Humans; D008297:Male; D011247:Pregnancy; D013933:Thumb; D014061:Tongue Habits; D014429:Twins, Dizygotic; D014430:Twins, Monozygotic