Building Self-Confidence is the title of an audio cassette tape manufactured and marketed by the Gateways Institute of Ojai, California. When the tape is played at a comfortable listening volume, all one hears is the rhythmic ebb and flow of a tropical ocean surf and the faint cry of gulls circling the shoreline.
At least, that is all one hears consciously. According to an accompanying brochure, the tape also contains dozens of positive suggestions or affirmations, such as: “I am a secure person. I believe in myself more and more every day, and my confidence naturally rises to the surface in every situation.” Each of these statements is repeated hundreds of times in the course of the 1-hour program. Because the suggestions are masked by the ocean sounds, they cannot be perceived consciously. Nevertheless, according to the same brochure, these suggestions can be and are perceived subconsciously, and therein lies their purported power. The contention is that consciously imperceptible or subliminal messages
reach the subconscious mind, which is the seat of all memories, knowledge and emotions. The unconscious mind has a powerful influence on conscious actions, thought, feelings, habits, and behaviors, and actually controls and guides your life. If you want to make real, lasting changes and improvements in any area of your life, you must reach the subconscious mind where the changes begin.
For a busy person who lacks self-confidence and lives on a tight budget, the Building Self-Confidence tape in question would seem to have strong appeal. It retails for $12.95 in the United States and, like several other Gateways Institute tapes, comes in a small carton carrying the advertisement: “Subliminal tapes work, so you don't have to. . . .
Simply play the tapes while you work, play, drive, read, exercise, relax, watch TV, or even as you sleep. No concentration is required for the tapes to be effective. They work whether you pay attention to them or not.” The brochure also notes:
A script is provided with each tape so you know the exact recorded subliminal message. It is not necessary to read the script while listening to the tape, although to enhance effectiveness, we suggest you use statements on the script as positive affirmations, repeating them to yourself from time to time. Many have found it very helpful to read the script aloud once each day just before going to bed at night.
To maximize results, play your subliminal tape at least once a day. The more often the tape is played, the faster and greater the effect. Because each person is unique, individual results will vary from person to person. Results are sometimes experienced within the first few playings, while in other cases it may take a few days or several weeks to see changes. Be assured that if you faithfully use the tape on a regular, daily basis, results will come.
Building Self-Confidence is but one of many subliminal self-help products sold by Gateways Institute, and Gateways is but one of many sources of such merchandise. According to one estimate (Oldenburg, 1990a), about 2,000 individuals or companies in America and Canada now produce subliminal self-help products for retail sale. That there is money to be made selling such products is suggested by a second estimate (Natale, 1988) that in 1987 American consumers purchased $50,000,000 worth of subliminal tapes intended for their personal improvement, a 10 percent increase over 1986 sales. Thus the subliminal industry is big and, by most accounts, getting bigger (see McGarvey, 1989; Moore, 1982; Natale, 1988; Oldenburg, 1990a).
It is easy to see why, for several reasons. First, the premise underlying subliminal suggestion—that a person can effortlessly accomplish in a matter of months or even weeks what others struggle but fail to do in a lifetime—is nearly irresistible (see Oldenburg, 1990a).
Second, as Oldenburg (1990a) has also pointed out, the promise of subliminal suggestion seems as inviting as its premise. To clarify, consider the catalog of products produced by Potentials Unlimited of Grand Rapids, Michigan. This catalog cites more than 100 subliminal programs that are claimed to aid people lose weight, stop smoking, quit drinking, think creatively, make friends, reduce pain (whether due to arthritis, migraines, or premenstrual syndrome), improve vision, restore hearing (a particularly difficult goal to attain through subliminal auditory suggestions, or so it would seem), cure acne, conquer fears (of death, driving, or flying, among others), read faster, speak effectively, handle criticism, alleviate depression, assuage guilt, project astrally, heal psychically, mentally travel through space or time or both (e.g., imagine visiting Atlantis or searching for hidden treasure in the Sphinx), and become a
better bowler. Though this partial listing provides a sense of the remarkably broad range of problems and issues that are allegedly amenable to hidden messages, it does not capture the subtle yet seemingly crucial differences that exist among the various subliminal programs · For example, Potentials Unlimited offers two programs, Divorce—Yes (“If you seek the divorce, this tape can free you from the other person. ”) and Divorce—No (“If you don't want a divorce, yet have no choice, quiet your fears and regain confidence to live and love again·”): one can only hope that the company exercises as much care and caution in filling customer orders as they presumably do in producing their subliminal tapes, for the consequences of a mix-up might be catastrophic.
Yet a third reason for the rapid growth of the subliminal industry is tied to both the proliferation of new products and the development of new technologies. Though “pure” subliminal audiotapes—those containing virtually no audible messages—remain a fixture in the marketplace, “mixed” tapes, featuring subliminal messages on one side and supraliminal suggestions for guided relaxation and visualization on the other, are becoming increasingly popular. In both cases subliminality is achieved either by the traditional method of masking suggestions with the sound of music or waves or by the newer technique of speech compression, whereby the voice track bearing the suggestions (as many as 100,000 per hour) is accelerated until it becomes an unintelligible high-pitched whine. Although speech-compression technology is disavowed by some companies, including Gateways Institute, it is endorsed by others, including the Psychodynamics Research Institute in Zephyr Cove, Nevada, a firm that is also notable for being among the first to sell subliminal programs for children, including a potty-training tape for toddlers (see Oldenburg, 1990a).
To complement their line of subliminal audio programs, many companies now also offer an array of subliminal video tapes, in which suggestions are shown so briefly that they cannot be consciously seen. This procedure is part of the latest high-tech subliminal innovation, called MindVision, that was introduced in November 1989 by Gateways Institute. As described by Oldenburg (1990b:C5):
. . . this “inconspicuous box” hooks into the television and VCR to flash visual subliminal messages “hundreds of thousands of times each hour” on the TV screen while repeating auditory subliminal affirmations all during regular TV shows. “The lazy man's answer to a better life,” Gateways boasts.
But is it really? More to the point, what evidence is there that mass-marketed subliminal self-help products are effective in practice? Even more fundamental, is there any scientific evidence that such products, in principle, could be effective?
SUBJECTIVELY PERCEPTIBLE VERSUS OBJECTIVELY DETECTABLE STIMULI
The question of effectiveness in principle has been addressed by Merikle (1988). In the introduction to his article, he remarks that, although the reality of subliminal perception continues to be a contentious issue in scientific circles, “recent research has led to a growing consensus that subliminal perception is a valid phenomenon that can be demonstrated under certain well-defined conditions (Merikle, 1988:357). 1 The research to which Merikle refers has revealed two important observations that, taken together, provide strong support for subliminal perception. First, performance on a variety of psychological tasks—for instance, deciding whether a string of letters forms a word (e.g., Marcel, 1983), whether a word has a good or bad meaning (Greenwald et al., 1989), whether an ambiguously described person is friendly or hostile (Bargh and Pietromonaco, 1982), or whether a geometric shape seems light or dark (Mandler et al., 1987) is influenced by information that people claim they did not consciously perceive. Second, information presented above and below the level of claimed awareness has qualitatively different effects on performance (e.g., Dixon, 1971; Cheesman and Merikle, 1986; Groeger, 1984; Jacoby and Whitehouse, 1989). The importance of the second observation lies in the fact that, given the demonstration of differential (possibly opposite) outcomes, “one can be certain that effects observed in the supposedly unaware condition were not actually due to the subjects ' being aware of an item without the experimenter's detecting that awareness” (Jacoby and Whitehouse, 1989:127).
Why the emphasis on claimed awareness? The answer is suggested by the results of a study by Cheesman and Merikle (1984) in which subjects were asked to name, as quickly as possible, a “target” color (a patch of blue, for instance) that was preceded by either a congruent or an incongruent color-word “prime” (the word blue as opposed to, say, green). In previous studies using visible color words as primes (e.g., Dyer and Severance, 1973), it had been shown that a target color is named faster if it is preceded by a congruent than by an incongruent prime. Whether color words rendered invisible by backward masking also produce a reliable “priming effect” in the color-naming task was an issue of central concern in Cheesman and Merikle's study.
To investigate this issue, Cheesman and Merikle measured color-naming latencies under three threshold conditions: suprathreshold, objective, and subjective. Each of these conditions comprised many individual trials, and every trial conformed to the same sequence of events in rapid succession: (1) presentation of a congruent or an incongruent color word prime, (2) presentation of a central mask composed of random letters, (3) display of the to-be-named target color.
The critical difference among the conditions was the duration of the interval separating onset of the prime from onset of the mask: a constant 300 milliseconds (msec) in the suprathreshold condition, an average of 56 msec in the subjective-threshold condition, and an average of 30 msec in the objective-threshold condition. Cheesman and Merikle settled on these intervals, or stimulus onset asynchronies (SOAs), by pretesting the subjects on the ability to detect which one of four color-word primes had been presented on a particular trial.
Results of this pretesting revealed that at the SOA corresponding to the suprathreshold condition, subjects stated that they could see the primes clearly, and they therefore estimated their performance on the test of four-alternative forced-choice target detectability would be perfect (100 percent)—which it was. At the SOA corresponding to the objective threshold, subjects indicated that they could not see the primes, and they therefore anticipated scoring at chance (25 percent)—which they did—on the test of target detectability. At the SOA corresponding to the subjective threshold, subjects again claimed that they could not consciously perceive the primes, and they therefore again anticipated scoring at chance as to which particular target color word had been presented on a particular trial. In actuality, however, their random “guesses” were, on average, 66 percent correct—a level of detection performance that plainly exceeds chance.
As the detectability of the primes varied across threshold conditions, so too did the size of the priming effect observed in the color-naming task. In the suprathreshold condition, a substantial priming effect was found (on average, target colors were named about 95 msec faster when primed by congruent than by incongruent color words); in the subjective-threshold condition, the effect was smaller but remained significant (mean difference of roughly 40 msec); and in the objective-threshold condition, the effect was virtually nonexistent (mean difference of less than 10 msec).2 These results, in addition to those relating to tasks other than color naming (see Eriksen, 1960, 1986; Merikle, 1988), suggest that subjectively imperceptible but objectively detectable stimuli can affect certain actions. As such, these results are consistent with Merikle's (1988:360) conception of subliminal perception as “perception in the absence of subjective confidence.”
There is one advantage of viewing subliminal perception this way (Merikle, 1988:360):
It eliminates much of the mysticism previously associated with the concept. No longer is it necessary to consider subliminal perception as implying the existence of some “supersensitive” unconscious perceptual system. Rather, the evidence simply suggests that we can sometimes discriminate among stimulus states, as indicated by our verbal responses, even when, based on our subjective phenomenal experiences,
we have no confidence that sufficient stimulus information was perceived to guide response selection. Thus, according to this view, subliminal perception occurs whenever we can objectively discriminate among possible stimulus states but have no subjective confidence as to the correctness of our decisions.
A second advantage concerns the question, posed earlier, of whether it is possible in principle for mass-marketed subliminal self-help products to produce their intended effects. By Merikle's (1988:360) account:
When subliminal perception is viewed as a subjective state, there is a very clear specification of the minimum stimulus condition that must be satisfied before sufficient information is perceived, either consciously or unconsciously, to influence higher-level decision processes. Since, according to this view, subliminal perception reflects an absence of subjective confidence when responding discriminately to a stimulus, the minimum condition necessary for demonstrating subliminal perception is the presence of a detectable stimulus.
To determine whether subliminal self-help products, specifically, subliminal audio cassettes, meet this “minimum stimulus condition, ” Merikle (1988) performed two types of studies. First, if the cassettes actually contain covert messages, then frequency changes characteristic of spoken speech should be evident in spectrograms or “voice prints ” derived from the tapes. Of the 40-odd spectrograms that Merikle culled from four subliminal audio cassettes (each produced by a different company), none showed any signs of hidden speech.
Though provocative, these null results are difficult to interpret because spectrographic analysis may not be capable of detecting very weak speech (e.g., at average signal-to-noise ratios of−10 to −20dB, see Borden and Harris, 1984). In addition, it is conceivable that in comparison with a sound spectrograph, the human auditory system is more sensitive to the detection and decoding of weak, degraded signals (i:e., embedded messages). In recognition of this possibility, Merikle (1988) performed a second type of study in which the human auditory system, rather than a sound spectrograph, served as the measuring instrument. In this psychophysical research, subjects were repeatedly tested for the ability to discriminate between two commercially produced cassettes that were identical except that, according to the manufacturer, one contained subliminal messages and the other did not. Merikle found that the subjects could not reliably distinguish between the “message” and the “no-message” cassettes, and he concluded (1988:370):
Taken together, the empirical results lead to the inescapable conclusion that the widely marketed subliminal cassettes do not contain any embedded messages that could conceivably influence behavior. This conclusion is supported both by the results of the spectrographic analyses indicating that these cassettes do not contain any identifiable embedded speech and by the results of the psychophysical studies
indicating that these cassettes do not contain any embedded signals whatsoever that can be detected under controlled conditions. Given that consistent empirical support for subliminal perception has only been found under conditions that allow stimulus detection, these subliminal audio cassettes do not satisfy the most minimal conditions for demonstrating subliminal perception.
An ardent advocate of subliminal self-help might challenge this conclusion on two grounds: (1) some, perhaps many, of the vast number of the audiotapes (or any or all video tapes) that Merikle did not test do meet his minimum condition for demonstrating subliminal perception and thus could conceivably affect behavior as advertised; (2) some, perhaps many, of the people who buy and use these tapes say that “silent treatments” do them good (see McGarvey, 1989; VandenBoogert, 1984). We first consider in detail the second point and then discuss the implications of the first point.
MOBILIZATION, EFFORT JUSTIFICATION, AND EXPECTANCY EFFECTS
As noted by Oldenburg (1990a), many marketers of subliminal self-improvement products try to attract new customers by publicizing the ringing recommendations of past patrons. Oldenburg (1990a) cites several of these endorsements, and others may be found in Discoveries Through Inner Quests, a promotional magazine for the Gateways Institute. In the Winter-Spring 1990 issue of this magazine, a woman from Massachusetts writes: “Bless you! I'm listening to my tape on pain reduction. It is marvelous. I had almost instant relief from pain on first using it a few days ago. It's much cheaper than a doctor and much better than medication. Phenomenal is what it has done for my spirits.” In the same issue, a California woman reports “dramatic results” in her eating habits after purchasing the subliminal tape titled Stop Eating Junk Food, and a man from Maine states that shortly after receiving the tape Wealth and Prosperity, he got a new job and tripled his old salary.
Though there is no reason to doubt the sincerity of these testimonials, there are several reasons to question the conviction that subliminal suggestions are in any way responsible for, or even play a part in, any self-perceived improvements in behavior. In the first place, by buying and using a subliminal self-help product, one demonstrates not only a desire for personal enhancement, but also a commitment to change one's ways. The very act of making such a commitment, of mobilizing oneself into action, may be therapeutic in its own right, in much the same way that some people realize marked improvements in behavior after they register for, but before they receive, individual psychotherapy (see Rachman and Wilson, 1980). Compared with undertaking psycho-
therapy, the commitment expressed through the purchase and use of a subliminal product is obviously much less. After all, such products are designed to work “so you don't have to,” and its therapeutic potential is correspondingly much more modest in principle. Indeed, the commitment entailed in employing subliminal suggestions to, say, enhance one's popularity and make new friends seems comparable to the commitment involved in spending an hour every day for a month at the beach to accomplish these same goals. After visiting the beach on a regular basis, or following the steady use of a “be more popular” subliminal tape, one might in fact acquire some new friends. But surely this outcome is no more attributable to the properties of the beach than it is to the contents of the subliminal tape. Rather, responsibility rests with the person's decision to do something—go to the beach or play the subliminal tape—that might help him or her win friends. Consequently, the imaginary “beach therapy” might be every bit as effective, or ineffective, as the real “subliminal programs” that are purported to improve one's popularity.
A second, related reason that subliminal tapes, even those containing no detectable embedded messages, may seem salutary has to do with the social psychological phenomenon of effort justification: the finding that the harder we work at something, the more we like it (see Penrod, 1983). After buying a subliminal tape and using it daily for several weeks, as most manufacturers advise, many people would be reluctant to admit to themselves or others that they had wasted their time and money. Instead, they would be motivated to detect some sort of change in some aspect of their lives, in order to rationalize their investment (see Conway and Ross, 1984).
Yet a third reason for the possible effect of tapes without detectable messages, perhaps the most important, relates to expectancy effects. By way of background, most readers are familiar with the story of how, in 1957, an advertising expert named James Vicary subliminally presented the statements “Eat Popcorn and Drink Coke” to unsuspecting viewers of the film Picnic, resulting in an impulsive rush to the refreshment stand. Many readers may not know, however, that years later Vicary admitted that his study was a hoax intended to increase revenues for his foundering advertising firm (see Weir, 1984). Vicary's “demonstration” sparked a storm of controversy (see Moore, 1982, 1988; Pratkanis and Greenwald, 1988) and stimulated many investigations of subliminal advertising. One of these was a study, brought to our attention by Pratkanis et al. (1990), that was conducted by the Canadian Broadcast Corporation in 1958. As described by Pratkanis et al. (1990:5):
During a popular Sunday night television show viewers were told about the Vicary EAT POPCORN/DRINK COKE STUDY and were informed that the station would
do a test of subliminal persuasion (although the content of the message was not revealed). The message “Phone Now” was then flashed subliminally on screen 352 times. Telephone company records indicated that phone usage did not increase nor did local television stations report an increase in calls. However, almost half of the nearly 500 letters sent in by viewers indicated that they felt compelled to “do something ” and many felt an urge to eat or drink. It appears that expectations created by the Vicary study influenced what people believed had happened.
That subliminal methods of personal improvement, like those involved in public advertising, are susceptible to strong expectancy effects is a point made plain in a recent study by Pratkanis et al. (1990). 3 Through ads placed in local newspapers, these researchers recruited volunteers who were especially interested in the potential value of subliminal self-help tapes and who would probably be similar to those most likely to purchase such products.
On the first day of the study, the subjects completed a battery of tests to measure self-esteem and memory ability. Every participant was then given one or two commercially produced subliminal audiotapes: one claimed by the manufacturer to contain suggestions for improving self esteem (e.g., “I radiate an inner sense of confidence”), the other claimed to contain suggestions for improving memory (e.g., “My ability to remember and recall is increasing daily”). On both tapes, the suggestions were recorded behind background classical music, so as to render them subliminal. The intriguing aspect of this study was that only a randomly selected one-half of the subjects actually got the tape they thought they were getting, one-quarter received the memory enhancement tape mislabeled as one to improve their self-esteem, and one-quarter received a self-esteem tape mislabeled “memory improvement.”
The subjects took their tapes home and listened to them every day for 5 weeks, the period recommended by the manufacturer for achieving maximum benefit. After 5 weeks, the subjects were asked to indicate whether they believed the tapes had been effective, and they also completed a second battery of self-esteem and memory tests.
The tests showed that the tapes had no appreciable effect, positive or negative, on any measure of either self-esteem or memory, but many of the subjects believed otherwise. Approximately one-half of those who thought they had received the self-esteem tape—regardless of whether they had actually received it or the memory tape—stated that their self-esteem had risen; similarly, about one-half of those who presumed, correctly or not, that they had received the memory tape maintained that their memory had improved as a result of listening to the tape. In light of those results, the title selected by Pratkanis and his associates to describe their study—“What you expect is what you believe, but not necessarily what you get”—seems most appropriate.
There are some well-documented psychological reasons that subliminal self-help products may appear to work, even if they contain no detectable embedded messages and thus fail to satisfy the “minimum stimulus condition” set by Merikle (1988) for demonstrating subliminal perception. It is possible, of course, that products now available in the marketplace do meet the criterion of detectability (after all, Merikle tested no video displays and only a handful of audio cassettes) or that such products could be engineered in the future. Suppose, for the sake of argument, that one were to identify or invent a subliminal self-help-product that complies with the minimum prerequisite. What then?
Clearly, the mere presence of objectively detectable messages would by no means ensure the product's effectiveness. Recent research does suggest that subjectively imperceptible stimuli may have short-term effects on the performance of such relatively simple tasks as color naming or lexical decision under controlled laboratory conditions. But one cannot and should not infer from this research that long-term changes in complex actions, cognitions, or emotions—such as smoking, self-confidence, or depression—can be effected by exposure to subliminal suggestions under such varied real-life circumstances as reading, relaxing, or even sleeping. Such effects, if any, remain to be conclusively established and rigorously explored.
Rather, as Merikle (1988) has remarked, the presence of detectable messages would only imply that it may be worthwhile to carry out carefully controlled studies of the possible effects of such messages. Such studies would need to address a very long list of questions, some of which have been raised in prior research on subliminal perception. For instance, are there significant individual differences in peoples ' sensitivity to the embedded but detectable messages (e.g., Sackeim et al., 1977)? Might one's receptivity to such messages be enhanced by the adoption of a passive attitude or frame of mind (e.g., Dixon, 1971)? Do subliminal messages serve only to amplify preexisting tendencies or can they induce novel ways of acting, feeling, or thinking (e.g., Kihlstrom, 1987)? Are there demonstrable qualitative differences between the effects of presenting one and the same message above as opposed to below the subjective threshold of awareness (e.g., Cheesman and Merikle, 1986; Dixon, 1986)? Finding answers to these and many related questions will doubtless prove to be a difficult and demanding task, but perhaps a rewarding one as well. At this time, however, on the basis of the committee's review of the available research literature, we conclude that there is neither theoretical foundation nor experimental evidence to support claims that subliminal self-help audiotapes enhance human performance.
1. In the interests of brevity and in keeping with our current focus on subliminal perception as a commercial means of promoting self-improvement, neither the history nor the current status of subliminal perception as a scientific concept is discussed in detail here. Readers interested in these issues should consult Adams (1957), Cheesman and Merikle (1984, 1986), Dixon (1971, 1981), Eriksen (1960), Goldiamond (1958), Greenwald et al. (1989), Holender (1986), and accompanying peer commentaries, Marcel (1983), Merikle and Cheesman (1987), Reingold and Merikle (1988), and Swets et al. (1961).
2. In addition to manipulating the prime-mask SOA, Cheesman and Merikle (1984) varied the prime-target color SOA, either 50, 550, or 1,050 msec. Because this latter variable did not significantly influence the size of the observed priming effects, the results for each prime-target color SOA have been averaged to yield the above priming data.
3. This study is also described in Greenwald et al. (1990), together with two successful replications.
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