“discovery” is an inappropriate word, for the general idea of extinction--like that of conditioning--was well known in folklore, even if the philosophy of Associationism had never given it formal recognition. But it is a long step from knowing that the villagers eventually will cease to respond if one repeatedly cries “Wolf”, to the specification of the conditions under which the process will occur. Moreover, the facts of experimental extinction seemed to run counter to the Associationists’ Law of Frequency, which made the “discovery” of extinction that much more difficult.
Extinction sometimes is treated merely as a technique for the elimination of previously conditioned responses. Such impressions miss the significance of the phenomenon: Extinction does not involve a simple unstacking of the associations built up through conditioning; it is an active process in which something new is learned about the environment.