Talit over ones head during tefilla

Question

I have always understood that according to the Mishna Berura, only a Talmid Chochom should enwrap himself in a Talit during tefilla. I have always been bothered that the first thing Baalei Teshuva and others who may not be learned will do is cover their heads with a Talit. It may be a fault of mine, to think that way, but what is the Halacha, if there is one? Thank You