Understanding Psychology (10th Ed)

 
Module 17 
Classical Conditioning 
181
how people and animals learn; indeed, Pavlov was wrong in some of his basic 
assumptions (Hollis, 1997). 
For example, according to Pavlov, the process of linking stimuli and responses 
occurs in a mechanistic, unthinking way. In contrast to this perspective, learning 
theorists infl uenced by cognitive psychology have argued that learners actively 
develop an understanding and expectancy about which particular unconditioned 
stimuli are matched with specifi c conditioned stimuli. A ringing bell, for instance, 
gives a dog something to think about: the impending arrival of food (Kirsch et al., 
2004; Rescorla, 198). 
Traditional explanations of how classical conditioning operates have also been 
challenged by John Garcia, a learning psychologist. He found that some organisms—
including humans—were biologically prepared to quickly learn to avoid foods that 
smelled or tasted like something that made them sick. For instance, a dog quickly 
learns to avoid rotting food that in the past made it sick. Similarly, if every time you 
ate peanuts you had an upset stomach several hours later, eventually you would 
learn to avoid peanuts. In fact, you might develop a learned taste aversion , so that 
peanuts no longer even taste good to you (Garcia, 1990, 2003). 
The surprising part of Garcia’s discovery was his demonstration that condition-
ing could occur even when the interval between exposure to the conditioned stimu-
lus of tainted food and the response of sickness was as long as eight hours. 
Furthermore, the conditioning persisted over very long periods and sometimes 
occurred after just one exposure. 
These fi ndings have had important practical implications. For example, to keep 
crows from stealing eggs, dairy farmers may lace an egg with a chemical and leave 
it in a place where crows will fi nd it. The drug temporarily makes the crows ill, but 
it does not harm them permanently. After exposure to a chemical-laden egg, crows 
no longer fi nds them appetizing (Baker, Johnson, & Slater, 2007; Cox et al., 2004; 
Green, Henderson, & Collinge, 2003).