29Subliminal messages in music?
Is there an effect of subliminal messages in
music on choice behavior?
Hauke Egermann, Reinhard Kopiez
Hanover University of Music and Drama,
Institute for Research in Music Education, Germany
Christoph Reuter
Institute for Applied Musicology and Psychology, Cologne, Germany
The present study examines the effects of subliminal text messages in music
on choice behavior. Subliminal messages are assumed to function as auditory
primers. The results of two experiments will be presented: In Experiment 1,
the authors tried to manipulate choice behavior of adult students (N = 66; age:
19-30 years) using subliminally presented
s in two pop music pieces. In two
blinded, non-directed listening tasks, subjects had (a) to choose one word out of
ten from a list of words (condition wordlist), and (b) to indicate which drink they
would like by putting a plastic chip into a box standing in front of four labeled
bottles of water (condition choice of drink). Musical examples without subliminal
messages were used as a control condition. No significant differences were found
between experimental and control conditions. In Experiment 2, children (N =
82; age: 7-11 years) served as subjects. Regardless of the task and age group, no
effects of subliminal messages on choice behavior could be observed. The paper
concludes with a general discussion about the lack of theories that could explain
any observed effects of subliminal manipulation.
Journal of Articles in Support of the Null Hypothesis
Vol. 4, No. 2
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Journal of Articles in Support of the Null Hypothesis. JASNH, 2006, Vol. 4, No. 230 31Subliminal messages in music?
The influence of music on consumer behavior has been investigated in the last
two decades (e.g., Milliman, 1982, 1986; North, 1996; North, Hargreaves & McKendrick,
2000). Studies have revealed that musical tempo and customers‘ music preferences are the
best predictors for strength of influence. Slow music and appreciation for the respective
musical style can, for example, affect the length of stay of supermarket shoppers or
restaurant patrons. However, there are only a few studies on the effect of music on choice
behavior. Groenland & Schoormans (1994) found that music can affect product evaluation
and product choice in a two-fold way: First, music can create a short-lasting association
between product and affective stimulus by mood induction; second, affective conditioning
can create a longer-lasting connection between a product and an affective stimulus (e.g.,
music). In a field experiment, North et al. (1997; North, Hargreaves & McKendrick) showed
that stereotypical folk music with strong national associations, such as German “Bierkeller”
music or French accordion music, can activate related knowledge between the product (e.g.,
wine) and the respective country. The use of French music led to French wines outselling
German ones, whereas playing German music led to the opposite effect on sales of French
wine. Customers were unaware of these effects. This finding sheds an interesting light on
the role of consciousness in advertisement, a topic which is currently under discussion in
consumer research. Dijksterhuis et al. (2005) has argued that consumer choice is much more
based on unconscious processes than previously assumed and is, for example, affected by
environmental features. Following this approach, Chartrand (2005) has proposed building
a more comprehensive model of nonconscious processes in consumer behavior. Our study
is a contribution to the current discussion of the role of nonconscious perception.
In everyday life, it is a widespread belief that worded messages can be embedded
and hidden in music with the intention of manipulating the listener’s behavior. Many have
claimed that subliminal techniques are used for advertising and propaganda purposes.
For example, in the movie Josie and the Pussycats (Elfont & Kaplan, 2001), the breathtaking
success of the band is based on subliminal advertising messages weaved into the songs by
the band‘s producer. In the past, many studies on subliminal manipulation or perception
have been undertaken (for a review see Merikle, 1988; Merikle, 2000; Ott, 1998; Theus,
1994). There is an ongoing interest in the field of subliminal stimulation, and a search for
the term “subliminal” in the psychological database PsycINFO results in more than 600
hits.
Subliminal perception is characterized by perception without awareness. This
characteristic is also emphasized in the definition of “subliminal message” by Merikle
(2000, p. 497) who defined it as „any situation in which unnoticed stimuli are perceived.“
For example, such stimuli might be inaudible to the conscious mind but audible to the
subconscious or deeper mind, or they may be images transmitted so briefly that they are
perceived only subconsciously. Following Cheesman & Merikle (1985), we can distinguish
between a “subjective” subliminal perception, which is characterized by subliminal stimulus
presentation with answers above chance level, and “objective” subliminal perception, which
is characterized by answers at chance level. Our study focuses on subjective subliminal
perception, also described sometimes as “subception” (Lazarus & McCleary, 1951).
By looking at review studies related to the topic of subliminal stimulation, it becomes
evident that there is a great interest in this subject. Scholars working on psychoanalytic
theory are especially interested in this topic. For example, Balay & Shevrin (1988) reviewed
studies by Silverman (e.g. 1975) who tried in numerous experiments to test his subliminal
Journal of Articles in Support of the Null Hypothesis. JASNH, 2006, Vol. 4, No. 230 31Subliminal messages in music?
psychodynamic activation (SPA) method. This method claims to activate subconscious
conflicts using subliminal stimulation. However, Balay & Shevrin noted that Silverman’s
results suffered from methodological weakness. The review study by Fudin & Benjamin
(1991) suggested that despite insufficient testing, auditory SPA seems to have several
methodological advantages over visual SPA. After analyzing the effects of subliminal
drive-related stimuli on behavior,
Bornstein (1990) concluded that
SPA has stronger effects than
superliminal stimuli. In another
study, Bornstein (1989) discussed
the use of subliminal stimuli as a
propaganda tool and concluded
that exposure to subliminal
stimuli can produce temporarily
stable changes in attitudes
and behavior. To summarize,
numerous studies have claimed
to provide evidence for an effect
of subliminal perception and
stimulation on behavior. However,
a critical review of a selected
number of studies on the effects
of subliminal acoustical messages
(SAM) and subliminal self-help
tapes (SHT) raises the question as
to whether or not there could be
an effect that is beyond a placebo
effect (see Table 1). As research on
subliminal manipulation started
with visual stimuli, we will first
discuss some studies from this field
which are relevant to our study.
Visual subliminal stimulation
One of the most prominent studies related to visual subliminal stimulation might
be the one undertaken by the consumer researcher James Vicary in 1957 (Moore, 1997;
Schneider, 2004; Theus, 1994). At the same time, the book The hidden persuaders by Packard
(1960) uncovered the highly specialized techniques of motivational manipulation in the
advertising industry. This information supported the claims of Vicary’s findings: This
information supported the claims of Vicary’s findings who had argued that he could raise
sales of Coca-Cola and popcorn in a cinema through subliminal visual advertising (to be
specific: the sales of popcorn by 58 % and the sales of Coca-Cola by 18 % over a period
of six weeks). Vicary had allegedly tested this technique by altering movies so that messages
urging viewers to “Eat popcorn!” and to “Drink Coke!” were displayed at regular intervals
throughout the movie.
Table 1. Survey of the results of selected studies on effects of subliminal acoustical
messages (SAM) and subliminal self-help tapes (SHT).
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Journal of Articles in Support of the Null Hypothesis. JASNH, 2006, Vol. 4, No. 232 33Subliminal messages in music?
These messages were presented so quickly (between 1/2000 and 1/3000 of a
second) that no one was aware of them. Vicary became very popular with his study, and
many people believe still today that his technique of advertising works. However, attempts
to replicate his results were unsuccessful (Vokey, 2002). Finally, in 1962, Vicary conceded
that he had faked his results; for him it was only a marketing trick. He never really found
an effect of subliminal advertising. Neverthelss, other researchers claim to have observed
similar effects. For example, Theus (1994) reported on a study that claimed to produce the
sensation of thirst through subliminal presentation of the word “Coke.” Another study
claimed to invoke the feeling of hunger through subliminal presentation of the word
“beef.” Although Vicary’s results were officially declared untrue, Wilson Key, the author
of the 1973 book Subliminal seduction, still “popularized the myth of subliminal advertising”
(Moore, 1997, p. 6). Key wrote a total of 4 books related to the alleged subliminal
manipulation of consumers (Vokey, 2002).
Current research in the field of subliminal visual perception has provided empirical
evidence of visual subliminal priming effects. Priming is defined as the process of activating
a mental representation and its connections to memory in relation to a perceived stimulus.
Through this activation, the connections will be more quickly accessible than they would
be if they were not primed by the stimulus. For example, in the study by Naccache, Blandin
& Dehaene (2002), subjects were required to decide whether a visually presented digit
between the range of 1 and 9 is greater or smaller than the target number 5. Before the
digits appeared, there was another digit which was presented subliminally. As a result, the
decision speed was increased when the subliminally presented digit was congruent to the
target stimuli by being greater or smaller than the digit 5. The authors concluded that
subliminal priming can activate a particular connection in the memory and make responses
faster. However, the priming effect disappears if the length of time between priming and
target stimulus is greater than 100 ms. Another very recent priming study was carried
out by Friedman et al. (2005), in which males who were subliminally primed with words
related to alcohol rated women as more attractive than when they were primed with words
not related to alcohol. Priming words were presented for a few milliseconds on the screen
before the attractiveness of a woman had to be evaluated in a subsequent picture. Words
related to alcohol were, for example, “wine” or “beer,” whereas words such as “coffee”
or “milk” were not related to alcohol. Still, the priming effect could be observed only in
subjects who preferred alcohol to stimulate their libido.
Keeping these results in mind, it is obvious that in the visual modality, the existence
of subliminal perception is very likely (Theus, 1994). However, these effects have only been
observed under laboratory conditions and their external validity remains to be confirmed.
Additionally, the reported studies only used very short examples; extended subliminal
messages that might influence behavior could not be applied (Ott, 1998; Vokey, 2002). None
of the presented studies concluded that a subliminal message could lead to a manipulation
of choice behavior as claimed by Vicary.
Auditory subliminal stimulation
The present study focuses on auditory subliminal messages. There are five ways to
embed worded messages in music: First, the target words or messages are placed in the music
below the auditory threshold and are, thus, masked by the music; second, it is possible to use
words with an inverted time-structure (so-called backward masked messages) and mix them
Journal of Articles in Support of the Null Hypothesis. JASNH, 2006, Vol. 4, No. 232 33Subliminal messages in music?
above the perceptual threshold (Walker, 1987); third, backward-masked messages can also
be used subliminally; fourth, highpass-filtered worded messages (containing frequencies
above 15 kHz) can be used (so-called “silent-subliminals”); finally, time-shrunk subliminal
messages (played back twice as fast as recorded) can be hidden in the music.
Although there is no profound research with experimental evidence in the field
of backward masking (Ott, 1998), the topic has often been of great public interest. For
example, in 1990 the heavy metal band Judas Priest had to face trial for mixing backward-
masked subliminal commands to commit suicide into their music (Moore, 1997; Schiller,
1990). The families of two fans who shot themselves accused the band of being responsible
for those horrendous incidents. Although the court found the band not guilty, the topic of
subliminal manipulation by backward messages has remained an issue nevertheless, despite
Vokey & Read’s (1985) convincing empirical evidence against any effects of stimulation
by retrograde messages (for similar findings see also Begg, Needham & Bokkbinder, 1993;
for similar findings see also Swart & Morgan, 1992). Their results showed that subjects
were unable to understand the semantic content of the messages in either a conscious or
subconscious way after listening to worded messages presented retrograde. In trying to affect
subjects‘ spelling of homophones, the authors could find no effects of subliminal stimulation
on behavior. The authors further noted that „the apparent presence of backward messages
in popular music is a function more of active construction on the part of the perceiver
than of the existence of the messages themselves“ (Vokey & Read, 1985, p. 1231). The
important role of expectation-guided perception of suggested backward messages could
also be demonstrated in the study by Thorne & Himelstein (1984). Despite these negative
results, there is an ongoing discussion about identifiable backward messages in rock music
(for an overview see Walker, 1985). To summarize, effects of backward masked messages
within music seem to be much more unlikely compared to subliminal (forward) masking
only. Thus, in our study we decided to use subliminal messages only without backward
masking or any other transformation.
Another interesting phenomenon of subliminal auditory messages is the use of
subliminal self-help tapes that claim, for example, to strengthen self-esteem, memory or
motivation. Rogers & Smith (1993) have amassed a market volume of about $50 million
for self-help audio tapes in the United States. In a telephone survey, 45 % of those who
participated believed that subliminal advertising would affect whether or not they would
buy the product being advertised. There are only a few studies that have claimed positive
effects of subliminal messages: Chakalis & Lowe (1992) found an improvement of the
experimental group in a face-name-occupation memory test; Merikle & Daneman (1996)
reviewed 44 studies on memory for events during anesthesia and found some evidence
for unconscious cognition in their meta-analysis. Specific information was remembered
following surgery, as long as testing was not delayed more than 36 hrs.
However, the majority of studies on the evaluation of self-help subliminal tapes as
used, for example, for weight reduction, increase of academic achievement, or increase of
self esteem, found only non-specific placebo effects of subliminal messages (e.g., Greenwald,
Spangenberg, Pratkanis & Eskenazi, 1991; e.g., Merikle, 1988; Moore, 1995; Russell, Rowe
& Smouse, 1991; Staum & Brotons, 1992). In a more recent study, Ott (1998) reviewed
numerous studies dealing with subliminal auditory messages and concluded that the ability
to control behavior through subconscious manipulation is very questionable.
Finally, the question remains as to how words in music can influence people if
they cannot actually hear them. Two answers can be given to this question: First, from a
Journal of Articles in Support of the Null Hypothesis. JASNH, 2006, Vol. 4, No. 234 35Subliminal messages in music?
modern psychological perspective there is evidence that the mere belief in the existence of
subliminal messages is sufficient to induce effects. Frequently, we can observe that subjects’
behavior is influenced by their presumptions about subliminal messages and not by the
information masked by the music (for experimental support see Greenwald et al., 1991;
Merikle & Skanes, 1992; Pratkanis, 1992). Second, stimuli below the listening threshold
can result in physiological reactions (e.g., change of heart rate, galvanic skin response, etc.).
Even in the case of unconscious perception, information processing on a physiological level
cannot be excluded. Experimental support can be found in the studies by Borgeat and co-
workers (Borgeat, 1989; Borgeat & Goulet, 1983). Physiological reactions also depend on
the content of messages: Compared to neutral target words, in the case of target words
with sexual connotations, physiological reactions failed to appear (Borgeat, Elie, Chaloult
& Chabot, 1985; Kotzé & Möller, 1990). Even messages perceived during anesthesia can
have an effect on postoperative smoking behavior (Hughes, Sanders, Dunne, Tarpey &
Vickers, 1994) or on memory for messages used in a postoperative sentence completion
task (Merikle & Daneman, 1996). To summarize, we cannot rule out that subliminal
messages can be perceived unconsciously and cause physiological reactions as indicators of
subliminal information processing.
The influence of age
Up until now, it has remained questionable as to whether there could be an
influence of age on sensitivity to subliminal stimulation. In 1963 Barber & Calverley (1963)
found that children between the ages of 6 and 12 were more susceptible to hypnotic-like
suggestions than were adults. A review of studies on suggestibility of children reveals that
children seem to be more susceptible to suggestive questions in an interview situation (e.g.,
Bjorklund, Cassel, Bjorklund & Brown, 2000). The assumption of a greater suggestibility
in children is also supported by consumer research: Oates, Blad