Moore summarized his arguments against subliminal advertising along two lines of reasoning:
1. Subliminal stimuli are usually so weak that they are not perceived by observers, and even if they are, they are usually nullified by other, strong stimuli present at the same time.
2. People are very much in control of their own overt responses to stimuli, and hence, even if they perceive subliminal stimuli, they can screen out any attempts to effect undesired behavior.
Moore continued the discussion in terms of two possible kinds of subliminal influence which he labeled “strong effects” and “weak effects”. “Weak effects” are said to be influences on emotional responses such as attitudes or wishes while “strong effects” are considered actual manipulations of buyer behavior. Moore contended that “weak effects” are unlikely because the stimulus energy of a subliminal stimuli are embedded among many others. According to him, It is most improbable that a subliminal stimulus could compete successfully with other supraliminal sources of stimulation. That is why such carefully controlled conditions are necessary for obtaining the effects in the laboratory <16>. He also argued that “strong effects” are improbable because the control that individuals have over their own overt behavior prevents undesired actions.
(2) Saegert’s arguments
Saegert argued that Silverman’s psychodynamic activation theory provided a conceptual basis for how changes in behavior might result from subliminal stimulation. Silverman’s theory is derived from the Freudian notion that unconscious wishes can serve to activate feelings within an individual, and these feelings may lead to specific behaviors. An example of one of Silverman’s theories is the hypothesis that severe feelings of depression result from the suppression of unconscious aggression wishes which cannot be expressed overtly in a socially desirable manner. According to him, these wishes are susceptible to aggression-arousing stimuli which in turn lead to turning of unconscious aggression against the self, thus activating greater feelings of depression. Silverman offered support for this psychodynamic activation principle through tachistoscopic presentation of subliminal stimuli.
However, Saegert said that even though Silverman’s theory is useful in outlining a plausible model of subliminal influence, at the same time, especially in an advertising context, it points out the great difficulty that an advertiser would have in developing a practical program to take advantage of subliminal advertising techniques. That is, stimulus conditions Silverman’s theory specifies make it highly unlikely that successful use of subliminal messages could be achieved in a promotional context. These include the following: (a) the wish to be heightened by the subliminal stimulus must be unconscious, (b) the message must be subliminal, (c) to be effective, the presented stimulus must precisely match the unconscious wish in psychological meaning. In addition, the advertiser should be careful indeed to assure that the desired responses are expressible in a socially acceptable way <24>.