James Dinsmoor states that "this theory is based on the reinforcing effect of stopping stimuli associated with shock and producing stimuli associated with the absence of shock (Dinsmoor, 2001, p. When a rat presses a lever and receives a shock, the lever is associated with the shock (Chance, 2008). In classical conditioning, the lever becomes a conditional stimulus for fear (Chance , 2008). In operant conditioning, if the shock is aversive, then the lever will also be aversive and the rat will be able to avoid it (Chance, 2008). negative by removing the aversive to increase a behavior (Chance, 2008) This is not a widely accepted idea.