The “primary reinforcement” hypothesis argues that many supposedly neutral stimuli really are primary reinforce, and hence are not really neutral. In many situations, it is possible to demonstrate the reinforcing effects of clicks, lights, snatches of song, momentary brightening of a TV picture tube, and countless other types of stimulation on the responses of birds, rodents, and primates of all varieties and ages. Because these effects cannot be attributed to prior pairing with other , known reinforce, they must (by definition) be primary reinforce
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