Invitation to Psychology

Chapter 6 Sensation and Perception 219

them to drink. Later, when given a chance to

drink, they did in fact drink more than control

subjects did, though only if they had been mod-

erately thirsty to begin with (Strahan, Spencer, &

Zanna, 2002).

But does this mean that advertisers can se-

duce us into buying soft drinks or voting for po-

litical candidates by slipping subliminal slogans

and images into what we watch and hear? Given

the many studies that have found no evidence of

subliminal persuasion in real life and the sub-

tlety of the effects that occur in the laboratory

(e.g., you have to already be somewhat thirsty

before you can be influenced to drink more),

we think there’s little cause for worry about

subliminal manipulation. It’s more appropriate

to be worried about the explicit manipulation of

your buying habits by advertisers tracking your

interests on almost every Internet site you visit.

And if you want to improve yourself or your life,

you’ll have to do it the old-fashioned way: by

working at it deliberately, with full awareness of

what you are doing.

Ever since then,
scientists have been
skeptical, but that has
not deterred people
who market sublimi-
nal recordings that
promise to help you
lose weight, stop smoking, relieve stress, boost
your motivation or self-esteem, improve your
memory, lower your cholesterol, or stop biting
your nails, all without any effort on your part. Ah,
if only those claims were true! But they are not. In
study after study, placebo recordings, which do not
contain the messages that participants think they
do, have been just as “effective” as those contain-
ing the supposed subliminal messages (Eich &
Hyman, 1992; Greenwald et al., 1991; Merikle &
Skanes, 1992).
Some efforts at studying subliminal persua-
sion may have left out an important ingredient:
the person’s motivation. A team of researchers
used subliminal messages—the words thirst and
dry—to make subjects feel thirsty and incline

About Subliminal

Persuasion

Thinking

CriTiCally

© Baby Blues Partnership. Reprinted with special permission of King Features Syndicate.

Recite & Review

Recite: Tell someone everything you can remember about perception without awareness, espe-

cially subliminal persuasion.

Review: Next, read this section again.

Now take this Quick Quiz:

A study appears to find evidence of “sleep learning”—the ability to perceive and retain material

played on an audio recording while a person sleeps. What would you want to know about this

research before deciding to play the audio version of this book by your bedside all night while you

slumber on, in hopes of not having to study when you’re awake?

Answers:

Study and Review at MyPsychLab

Was there a control group that listened to, say, a musical selection or white noise? How complicated was the material that was

allegedly learned: a few key words, whole sentences, an entire lecture by Professor Arbuckle? Were the results large enough

to have practical implications? How did the researchers determine whether the participants really were asleep—by using brain

wave measures or just unreliable self-reports?