Indirect Persuasion in Advertising: How Consumers Process Metaphors Presented in Pictures and Words

Edward F. McQuarrie, Santa Clara University
Barbara J. Phillips, University of Saskatchewan

Overview of Findings

It is rare to find a magazine ad that makes a straightforward claim like “Tide gets clothes clean.” Instead, detergent ads claim to make your clothes “as fresh and clean as sunshine,” or show a picture of a measuring cup filled with blue sky. These types of ads use metaphors where one thing, like sunshine, is compared to another thing, like clothes. Metaphors can be presented in words or in pictures. For example, if an advertiser wanted to persuade you that a cleaner named Blix removes stains, they could use a verbal metaphor like “Blix: Stain Grenade.” Or, they could use a visual metaphor by showing a picture of a bottle of Blix next to a hand grenade. Neither metaphor is anywhere near as straightforward as simply stating ‘Blix removes stains’. Why is it that advertisers avoid straightforward claims in favor of metaphors?

We argue that advertisers use metaphors instead of straightforward claims because metaphors are helpful in today’s media environment where bored and disinterested consumers try to avoid advertising. First, metaphors allow consumers to use their imaginations—metaphors encourage many positive associations with the product. For example, people who see the Blix ad with the grenade metaphor may think that Blix is a powerful stain remover. However, they might also think that Blix has explosive cleaning power, or that Blix will help them attack stains. Consumers might even think that Blix is a more powerful cleaner than other brands. If consumers generate this last thought, then the Blix ad is, technically speaking, misleading; an advertiser would not legally be able to state, flat out, that Blix is a superior brand, without empirical proof. In addition, consumers come up with these positive and potentially misleading associations themselves; they are not written in the ad. Consumers are less likely to argue against associations they came up with themselves, and more likely to remember and act on them.

We created sets of matched ads to test these ideas. Each set had the same message shown in one of three ways: (a) as a straightforward claim (e.g., “Plus dishwasher detergent clears away tough stains”), (b) as a verbal metaphor (e.g., “Plus dishwasher detergent bulldozes tough stains”), or (c) as a visual metaphor (e.g., a picture of a box of Plus dishwasher detergent beside a bulldozer cleaning off a dirty dish). We found that consumers thought that all three ads conveyed the same basic message (e.g., “Plus cleans difficult stains from dishes”). However, consumers who saw the ads with the verbal and visual metaphors had more positive thoughts about the product (e.g., “Plus is an industrial strength cleaner,” “Plus protects dishes from scratching,” and “Plus leaves no detergent residue on dishes”). Note that all of these thoughts would require proof if the advertiser stated them in a straightforward claim but that such proof was not provided. In addition, people who saw the visual metaphor ads created more positive thoughts than the people who saw the verbal metaphor ads. Furthermore, people appeared to come up with these positive thoughts immediately, as soon as they saw the visual metaphor ads. People who saw the verbal metaphor ads only came up with positive thoughts later, when questioned about the ads.

Significance of Findings

It has been suspected for many years that metaphors and pictures in ads may be unusually powerful persuaders, and that this power could readily be turned to deceptive purposes. However, before the present research, suspicion of the misleading potential of pictures and metaphors in ads rested on no more than … suspicion. Our study is the first to compare the persuasiveness of ads with metaphors to ads containing only straightforward claims, and to compare the impact of verbal versus visual metaphors in ads.

Our study confirmed the suspicion that metaphors encourage consumers to create many positive thoughts abut a product, including misleading positive associations. In addition, our research shows that consumers create positive thoughts as soon as they see a visual metaphor ad, but only after prompting for a verbal metaphor ad. Consequently, visual metaphors may be more effective at influencing consumers’ thoughts than verbal metaphors in the real world, because busy consumers are not usually prompted to think about ads.

Implications of the Research

The most important implication of this study is that advertisers may use metaphors in ads, especially visual metaphors, to encourage consumers to think positive thoughts about a product that could not be stated outright in a straightforward claim. The fact that these positive thoughts occur as soon as consumers view the ad means that it is difficult for consumers to guard themselves against these “extra” positive thoughts.

If it is true that consumers are peculiarly vulnerable to pictorial metaphors, then legal protections may need to evolve beyond a focus on whether a claim made in words is true or false. A new and more comprehensive standard would focus on whether a population of typical consumers does or does not spontaneously come up with certain thoughts when viewing an ad. The standard could no longer be that of what a reasonable man or woman would do, because it is not reasonable to infer from a picture of a cleaning product next to a grenade that this brand is more powerful than others. Nonetheless, based on the evidence of this study, it is an empirical fact that such thoughts do occur when consumers are exposed to visual metaphors. Whether the legal system can evolve to address the possibility of misleading claims delivered through pictures remains to be seen. At the least, this study argues for efforts to educate consumers to attend more closely to pictorial claims and to scrutinize them more critically.

Article Reference

McQuarrie, Edward F. and Barbara J. Phillips (2005), “Indirect Persuasion in Advertising: How Consumers Process Metaphors Presented in Pictures and Words, Journal of Advertising, 34 (2), 7-21.

Related Sources of Information

Gaeth, Gary J. and Timothy B. Heath (1987), “The Cognitive Processing of Misleading Advertising in Young and Old Adults: Assessment and Training,” Journal of Consumer Research, 14 (1), 43-54.

Kardes, Frank R. (1993), “Consumer Inference: Determinants, Consequences, and Implications for Advertising,” in Advertising Exposure, Memory, and Choice, Andrew A. Mitchell, ed., Hillsdale, NJ: Lawrence Erlbaum, 163-191.

McQuarrie, Edward F. and David G. Mick (2003), “Visual and Verbal Rhetorical Figures Under Directed Processing Versus Incidental Exposure to Advertising,” Journal of Consumer Research, 29 (March), 579-587.

Messaris, Paul (1997), Visual Persuasion: The Role of Images in Advertising, Thousand Oaks, CA: Sage Publications.

Phillips, Barbara J. and Edward F. McQuarrie (2002), “The Development, Change, and Transformation of Rhetorical Style in Magazine Advertisements 1954-1999,” Journal of Advertising, 31 (4), 1-13.

Stern, Barbara (1992), “Crafty Advertisers: Literal Versus Literary Deceptiveness,” Journal of Public Policy and Marketing, 11 (1), 72-81.

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