The Positive Effect of Negative Information

Accent the positive; eliminate the negative. Besides being the lyrics of an old Bing Crosby song, that phrase has been conventional wisdom for generations of marketers. After all, why would you want consumers to hear anything negative about your product? But like a lot of conventional wisdom, it doesn't stand up to serious scrutiny.

A study by researchers at the Stanford Graduate School of Business and Tel Aviv University found that small doses of mildly negative information — a so-called blemishing effect — may actually strengthen a consumer's positive impression of a product or service. The research could change the usual approach taken by marketers, for instance altering online ads or product descriptions on retail websites, or even face-to-face sales attempts.

"We find that as long as the negative information about a product is minor, your pitch [to a consumer] might be more persuasive when it calls attention to that negative, especially if consumers have already learned some positive things," said Baba Shiv, the Sanwa Bank, Limited, Professor of Marketing, at the business school.

The paper, "When Blemishing Leads to Blossoming: The Positive Effect of Negative Information," was coauthored by Danit Ein-Gar of the Recanati Graduate School of Business, Tel Aviv University; Zakary Tormala, associate professor of marketing at the Stanford Graduate School of Business; and Shiv.

To better understand the conclusion, consider an example presented by the authors.

Imagine that you are considering a new restaurant and reading reviews of it online. Most of the reviews are very favorable: great food, pleasant music, relaxed atmosphere. Then you come across a review that mentions that there is no parking nearby, a piece of information that is negative but not quite central to your value proposition for restaurants.

The conventional wisdom, as well as prior academic research, tells us that the bit of negative news would make it less likely that we'd go to the restaurant. And it might, if parking were the most important consideration. But if it were just one factor of many, the research indicates that it might well make the restaurant appear more attractive.

Here's why: When consumers receive mildly negative information after already receiving positive information, the "blemish" highlights the positive information and makes it seem even more positive, the researchers found. This boosts the impact of the positive information and promotes more positive evaluations, says Shiv.

However, the blemishing effect only occurs when the consumer is not focused solely on making the choice, a condition the researchers call "low processing." It's also important to note that the "blemishing" effect does not hold if the negative information is learned before the positive, or if the negative information is very strong.

Shiv and his colleagues hit upon the idea to study the blemishing effect by accident. "Danit [Ein-Gar] brought back a box of chocolates from Israel and some were broken," Shiv said in an interview. As they nibbled, the researchers wondered how the fact that the candies were broken would affect their perceptions.

They first did a preliminary study and saw that negative information could indeed strengthen a consumer's impulse to buy in some cases. The early data convinced the researchers that the blemishing effect was worth investigating.

To study the effect, the researchers set up four test groups of consumers and lab volunteers. Each group considered the purchase of one item: hiking boots (used with different methodologies in two separate groups), chocolate bars, or champagne glasses. In each study, the volunteers were presented with positive and negative facts about the products and were studied under both low-processing and the opposite or high- processing conditions. To be sure that the attributes the researchers thought were positive (or negative) were rated the same way by the volunteers, they first conducted a pretest, asking the subjects to rate various features.

In the first study, for example, some participants were told that the hiking shoes had a number of positive features, including designer orthopedic soles, were waterproof, came with extra shoelaces, and were available in many colors. Other participants got the same information, but were told the shoes only came in two colors, a mild negative. The hiking boots test was conducted online.

Some of the volunteers were distracted by being required to note how many times they looked away from the computer screen (a low-processing condition), while others weren't — the  high-processing condition.

The researchers found that when distracted, participants were more likely to have a favorable opinion of the boots when the description included some negative information along with the positive. But the effect was reversed when the volunteers were not distracted; they were more likely to favor the boots when the information they received was only positive.

In another study, conducted on a hot summer day, undergraduates were approached on a college campus with a pitch to buy chocolate bars. The chocolate had a number of desirable features — it was nicely chilled, described as a consumer favorite, and was being sold at a 50% discount. All of the students heard the same favorable information, but some were told the bars were broken.

To vary the processing effort, some students were approached as they entered a classroom to take an exam, while others were approached as they simply strolled around the campus. The researchers assumed that students on the verge of taking a test wouldn't focus on the candy, putting them into the low-processing category. But students who were more relaxed would probably give more thought to the question of how many candy bars to buy.

The results were similar to the hiking boots test. Students who were distracted by having to take a test bought more chocolate when they learned the bars were broken. Students who weren't distracted purchased more when they only heard positive information about the product. Their behavior demonstrated that the students weren't just failing to notice the negative information. They actually behaved differently, purchasing more candy than those who didn't get the negative fact.

Taken as a whole, the series of studies are a marked departure from earlier research on buying behavior and could serve to modify the strategies used by marketers. "In situations that encourage careful thinking, presenting exclusively positive information still does seem to be more compelling." But in less-focused settings — as is true of most online ads, for example — presenting some negative information has advantages, the researchers concluded.

Shiv says he has no concrete plans to do more research on blemishing. But he believes it would be interesting to follow up this research with an investigation of brain function and buying behavior with the aid of a functional MRI, an imaging technology that maps changes in blood flow within the brain in response to neural activity.

This piece originally appeared in Stanford Business Insights from Stanford Graduate School of Business. To receive business ideas and insights from Stanford GSB click here: (To sign up: https://www.gsb.stanford.edu/insights/about/emails)