My son took me to see a high school play recently, and I noticed that among the cast, the pretty/handsome/hot kids had the lead roles, and the cast was on average prettier than the supporting crew. I mentioned this to my wife, who was in drama club in high school, and she told me this was one of those things everyone knew – others would try out, but the prettiest kids were favored. The effect is strong, stronger than could be explained by a weak correlation between acting ability and prettiness.
If viewers prefer to watch pretty people, I can understand why commercial plays would favor the pretty. But I was surprised to see such transparent favoritism in what is supposedly an "educational" activity. I doubt parents would knowingly tolerate a high school math teacher giving higher grades to the pretty; why do they tolerate similar behavior from drama teachers?
My wife tells me that choir teachers favor pretty singers for choirs when many people will listen, but not when only a few will listen. Perhaps this is about parents and teachers wanting to make their school’s students look good in all ways compared to other schools?