Chapter 9 Learning and Conditioning 315ate a delicious filet mignon with béarnaise sauce,
he came down with the flu. Naturally, he felt
wretched. His misery had nothing to do with the
béarnaise sauce, of course, yet the next time he
tried it, he found to his annoyance that he disliked
the taste (Seligman & Hager, 1972).
Notice that, unlike conditioning in the labo-
ratory, Seligman’s aversion to the sauce occurred
after only one pairing of the sauce with illness and
with a long delay between the conditioned and
unconditioned stimuli. Moreover, Seligman’s wife
did not become a CS for nausea, and neither did
his dinner plate or the waiter, even though they
also had been paired with illness. Why? In earlier
work with rats, John Garcia and Robert Koelling
(1966) had provided the answer: There is a greater
biological readiness to associate sickness with taste
than with sights or sounds. Like the tendency to
acquire certain fears, this biological tendency prob-
ably evolved because it enhanced survival. Eating
bad food, after all, is more likely to be followed by
illness than are particular sights or sounds.
Explore the Concept Taste Aversion at
MyPsychLab
Psychologists have taken advantage of this phe-
nomenon to develop humane ways of discouraging
predators from preying on livestock, using condi-
tioned taste aversions instead of traps and poisons.
In one classic study, researchers laced sheep meat
with a nausea-inducing chemical. After eating it just
one or two times, coyotes and wolves still ran up to
lambs, but instead of attacking, they retreated, hid,
and threw up. They had developed a conditioned
aversion to sheep (Dingfelder, 2010; Gustavson
et al., 1974). Similar techniques have been used to
control other predators—for example to deter rac-
coons from killing chickens, and ravens and crows
from eating crane eggs (Garcia & Gustavson, 1997).Reacting to Medical Treatments
Because of classical conditioning, some medical
treatments can create unexpected misery, when
unpleasant reactions to a treatment generalize to
a range of other stimuli. This is a particular prob-
lem for cancer patients. The nausea and vomiting
resulting from chemotherapy often generalize to
the place where the therapy takes place, the wait-
ing room, the sound of a nurse’s voice, or the
smell of rubbing alcohol. The drug treatment is an
unconditioned stimulus for nausea and vomiting,
and through association, the other previously neu-
tral stimuli become conditioned stimuli for these
responses. Even mental images of the sights and
smells of the clinic can become conditioned stimuli
for nausea (Dadds et al., 1997; Redd et al., 1993).to do if you’re terrified of heights. They could
also “walk” out on a bridge and look down on a
fountain in the hotel lobby. During each session,
and again at one-week and three-month follow-up
sessions, the participants rated their discomfort
at each “floor.” Combining the therapy with the
drug reduced symptoms far more than combin-
ing it with the placebo. Further, in their everyday
lives, people who got the drug were less likely
than the controls to avoid heights.
Such research helps us to understand the
biological mechanisms that underlie our fears, and
the principles of behaviorism that may help us
control and even overcome them.
Accounting for Taste LO 9.5
Classical conditioning can also explain learned re-
actions to many foods and odors. In the laboratory,
behavioral scientists have taught animals to dislike
foods or odors by pairing them with drugs that
cause nausea or other unpleasant symptoms. One
research team trained slugs to associate the smell
of carrots, which slugs normally like, with a bitter-
tasting chemical they detest. Soon the slugs were
avoiding the smell of carrots. The researchers then
demonstrated higher-order conditioning by pair-
ing the smell of carrots with the smell of potato.
Sure enough, the slugs began to avoid the smell of
potato as well (Sahley, Rudy, & Gelperin, 1981).
Many people have learned to dislike a food
after eating it and then falling ill, even when the
two events were unrelated. The food, previously a
neutral stimulus, becomes a conditioned stimulus
for nausea or other symptoms produced by the
illness. Psychologist Martin Seligman once told
how he himself was conditioned to hate béarnaise
sauce. One night, shortly after he and his wife
Whether we say “yuck” or “yum” to a food may depend
on a past experience involving classical conditioning.