1.
Experimental results
The notion of subliminal perception
has generated substantial controversy for several decades, both within and outside
psychology. Although controversy persists, there seems to be little doubt that
observers’ responses can be shown to be affected by stimuli they claim not to
have seen (16).
The premise of subliminal perception
has been that the unconscious mind can receive information presented below the
threshold for conscious perception. The result may be attitude and even behavioral
change based on information that the individual is not consciously aware of
receiving <20>. Some psychology studies have shown the effects of subliminal
perceptions on the affective responses, and, in other research, experiments
have shown that subliminal stimuli can influence high-level cognitive processes,
including preferences for geometric shapes, liking of individuals, personality
judgments, and ratings of one’s self-concept. In addition, recent investigations
suggest that subliminally presented stimuli can influence behavior <4>.
However, with the possible exceptions of Hawkins’<6>,
Cuperfain and Clarke’s<3>, and Kilbourne, Painton, and Ridley’s<7>
studies, the empirical studies directed toward investigating subliminal effects
have failed to show conclusive results in an advertising context <24>.
Hawkins’ finding of increased thirst ratings following subliminal exposure to
COKE have been used as empirical evidence that subliminal advertising can directly
affect consumption-relevant behavior. However, Beatty and Hawkins who conducted
a replication study of Hawkins’ found no significant differences in the mean
thirst ratings <2>. In addition, Cuperfain and Clarke’s, and Kilbourne,
Painton, and Ridley’s studies contain so many methodological flaws that they
cannot be said to have advanced the case regarding any possible advertising
application <16>.
More recently, some evidence
suggests that subliminal messages may influence affective reactions to marketing
stimuli. For example, Aylesworth et al <1> found that sexually suggestive
subliminal embeds in an ad significantly increased upbeat feelings and significantly
increased negative feeling. However, they said that even though clearly, subliminal
embeds have some influence on the audience, it appears to very subtle and to
consist almost entirely of effects on feelings rather than cognitive measures.
And they added that the effects on feelings scales are in opposing directions
and may cancel each other out, and concluded that traditional ad measures such
as recall, attitudes toward advertisements and attitudes toward brands have
not been sensitive to the possible effects of subliminal advertising.
The major issue of subliminal
advertising is whether consumer exposure to subliminal stimuli can effectively
manipulate the behavior of consumers and provide advertisers with a tool to
bypass consumers’ defenses without their being aware of what is happening. Trappey
<26> conducted a meta-analysis to scientifically evaluate whether or not
subliminal marketing stimuli are an effective means for influencing consumer
choice behavior. After collecting the effect sizes of subliminal stimuli on
consumer behavior from 23 studies selected based on a predetermined set of rules,
he calculated a total of these 23 effect sizes. The resulting correlation coefficient
(r=0.0585) falls between the effect of aspirin on heart attacks (0.03) and the
relationship between alcohol abuse and a tour of duty in Vietnam (0.07), leading
to the conclusion that subliminal advertising has little influence on the consumer’s
decision to select between alternatives.