Contingency theorists argue that types of learning exist that are not explained by operant and classical conditioning. Contingency theory
proposes that for learning to take place, a stimulus must provide the subject information about the likelihood that certain events will occur. Robert Rescorla demonstrated that the pairing of a conditioned stimulus (CS) and unconditioned stimulus (UCS) does not always produce learning and contended that it is necessary for the CS to signify a contingency
Learned helplessness. Learned helplessness
, also demonstrated by Rescorla, results from situations in which no perceived connection (contingency) exists between a response and a reinforcer, suggesting to an individual that responses and outcomes are unrelated. When subjects' behavior has no effect upon reward, the result is apathy or unresponsiveness; they simply give up and no longer try. Martin Seligman also demonstrated that if individuals (both animal and human) believe they have no control in a situation, they exhibit learned helplessness, doing nothing and not trying to solve problems.