I do not believe appearance dictates ability, so whether a female is pretty or not, will not be the deciding factor in their debating skills. Furthermore, the term pretty can be very subjective and mean vastly different things, to many different people. Intelligence and communication are not decided by looks
Why would your attractiveness determine your intelligence/debating level? The stereotype of "pretty girls being stupid" is just that, a stereotype. Girls do not need to dumb themselves down or not engage in academic activities just because they're pretty, that is just an injustice towards themselves. It does not help them in the long run.