A 'cause that's the way I set my radio up to do it. I also set my radio up so that the lifting aileron moves farther than the dropping aileron because the lift caused by dropping the aileron also causes drag, and more drag on one wing causes yaw, and yaw causes less than axial rolls.

But now I have a question: Is it the dropped-aileron wing having lift that causes the banking, or the raised-aileron wing losing lift and dropping that does it? Seriously, don't gliders bank by using only the spoiler (or lifted aileron) on the inside wing?