As an Airbus FO there seem to be two types of capt - those whose left hand stays on their knee, and those whose left hand strays towards the stick (amazing how wide your peripheral vision can be
The maj are in the former - but it doesnt bother me either way, after all, its his signature. Intervention on ldg is a much less frustrating thing than constant, unasked for and unmonitored fiddling with the fcu during descent for example, which is just bleedin rude if you ask me (not that its happened recently and Im still sore of course.......)