Persuasive Advertising - J. Scott Armstrong [131]
Short words, short sentences, and simple punctuation are easier to understand, especially for poor readers. Given the widespread belief that brevity is a key aspect of clarity, readability formulas have sometimes been used by advertisers. For example, the Gunning Fog Index (see the Glossary)—in which the score approximates the number of years of schooling needed to understand the prose—has been used to evaluate and improve readability.
On the other hand, complex prose can make a weak argument seem more authoritative. Consider this example that I encountered in my review of papers for this book: “Positivity and negativity are further posited as having partially separable neurophysiological substrates that have functional outputs best viewed with multidimensional bivariate space as opposed to a single bipolar continuum.”
Complex prose leads readers to feel insecure about their ability to understand, and especially if their motivation is low, to assume that the arguments must be correct. Customers who lack expertise about a product category might defer to complex prose, especially if delivered by an expert. They might think, “Gee, he’s an expert, so it must be right.” This supports the old adage, “If you can’t convince them, confuse them.” Nevertheless, this does not strike me as a good way to develop long-term relationships with customers.
Evidence on the effects of clarity
The following lab experiments support clarity for strong arguments:
Simple writing improved recall and brand attitudes in print ads for a breakfast cereal. Three lab experiments were conducted on complex versus simple writing in ads for BRAN_NEW, a fictitious breakfast cereal. The ads included both strong claims (e.g., fat-free) and weak ones (lightweight packaging). In one of the experiments, 375 women viewed a TV commercial, some seeing a simple version and others a complex one. In the other two experiments, 94 subjects viewed print ads, again, some with simple prose and others complex. For each media, simpler prose aided recall and improved attitudes toward the brand only when an ad had strong arguments (Lowrey 1998).
High readability led to higher behavioral intent only with strong arguments. In a lab experiment using print ads for face cosmetics, when strong arguments were present and readability was high, behavioral intent was also high; however, poor readability cancelled the benefits of strong arguments. When the arguments were weak, the findings were reversed: better readability was associated with lower intentions (Chebat et al. 2003).
A review of almost 50 studies on readability scores found only a weak relationship to comprehension. Furthermore, using readability formulas to revise prose did little to improve readers’ comprehension (Anderson and Davison 1988). However, I suspect that the weak findings were due to the failure to consider whether there were strong arguments and whether the readers were involved.
The following experiments show that the use of complex prose can enhance the credibility of high-status sources. In one experiment, weak arguments about the benefits of plea bargains in criminal cases had no effect on attitudes when delivered in simple terms by either a low-status or high-statues communicator. When delivered in complex terms, they were persuasive only when the source was high-status (Hafer, Reynolds, and Obertynski 1996).
In another lab experiment, 54 mock jurors watched a videotaped trial in which two scientists provided evidence on whether a chemical, PCB, could have caused a plaintiff’s illness. When the testimony was not complex, jurors relied on the content of the testimony: the expert’s credentials had only a small influence because the jurors felt that they could understand the information. However, when the testimony was complex, they relied more heavily on the expert’s credentials when making their decisions (Cooper, Bennett, and Sukel 1996).
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