A quick reply - In transit.
What the last 2 respondants say is perfectly correct for an aircraft which only has aileron for roll control. For aircraft using aileron and roll spoilers, the spoiler is far more effective in roll control. Near the stall the spoiler dumps the lift on the rising wing more effectively than does the aileron, and, as a bonus, produces a little yaw in the direction desired.
Regards,
Old Smokey