Lord Love a Duck (1966)

An unusually gifted high school senior, Alan Musgrave (Roddy McDowall), decides to direct his mental powers toward helping an innocent new student, Barbara Ann Greene (Tuesday Weld), achieve her goal of popularity. With Alan's guidance, Barbara climbs the social ladder, finds a husband and eventually gets a shot at a glamorous movie career. But when Barbara's husband begins to get in the way of her ambitions, Alan will stop at nothing to make sure she reaches the top.