Why do aerlirons work in pairs?

[Seeker]

I know they do, but I also know that once the turn is initiated, rudder is used to correct the adverse yaw generated by the outside wing. If, however, only the inside aerliron operated, that off axis induced drag would obviate the need for rudder control in addition to lowering the total amount of induced drag. I'm aware that some of Lippisch's (Sp?) early designs used wing tip rudders in place of aerlirons/elevons, but I think they operated in pairs too.

I know there must be a reason why they operate in pairs, I just can't think of it.

Any one?

[Tyro48]

first off they operate opposed to make one side lift up while on the other side lift is directed downward, if only one aileron was working the side not working would have next to no drag as compared to the other side, this would cause serious yaw that would most likely need full rudder to compensate for, the slightest wrong move and the plane goes out of control, you've most likely experienced this having one aileron shot off and found the plane hard to control, different wing structures will affect how the plane reacts to this.