Why do advertisers use celebrities to endorse products that have nothing to do with that celebrity’s area of expertise? For example, a cricketer is unlikely to know much about cars or construction materials, and yet companies may use him to endorse a particular brand of car or a national brand of cement.

Obviously, if such endorsements weren’t effective, advertisers would have figured it out a long time ago and stopped using them.

Given the fact that we continue to see such examples, these endorsements must be effective. But, why do they work so well? Why do people assign credibility to celebrities in areas that are clearly outside their domain of excellence or knowledge?

People do so because our perceptions of a particular trait are strongly influenced by what we know about that entity from another context. This effect is known as the “halo effect" and has been widely documented in a variety of situations.

Unwarranted assumptions

In a classic experiment, researchers found that if a supervisor rated a subordinate high on one trait, he was more likely to rate the subordinate highly on other traits as well.

Similarly, we tend to attribute qualities such as kindness, intelligence, honesty, and merit to individuals who are good-looking.

Good looks have been shown to have a significant effect on a politician’s ability to garner votes and a candidate’s chances of getting a job. Recent research has even shown that all else being equal, better-looking people get paid higher salaries and are more likely to receive better treatment in the legal system. More attractive defendants are more often found innocent and receive shorter sentences even when convicted.

The most interesting part of these findings is that people did not even know that they were taking a person’s looks into consideration while making these judgements. Researchers have found that people tend to attribute their liking of someone to a variety of other factors, and rarely to the physical attractiveness of the individual.

The halo effect is not unique to individuals. Even brands can enjoy the benefits of the halo effect.

Imagine Sony deciding to get into the automobile business. What kind of cars would it make? Or if Rolex decides to introduce fashion sunglasses. Will these glasses provide good UV protection? You bet! Well, but how do we know?

If you think about it, the pre-assigned credibility of Sony and Rolex is because of the halo effect. “If Sony can make good electronic products, its cars should be well-engineered too."

The problem with this line of logic is that Sony doesn’t have any experience or expertise in manufacturing automobiles, and its current knowledge may not be transferable into this new domain. Yet, we start out with the presumption that it will make good cars.

There is also a flip side of the halo effect, where we start out with a negative impression of a person and then carry on that impression to other traits.

For example, you may come across an individual with large tattoos on his forearms and may automatically assign certain personality traits to him without knowing anything about that person.

You may assume that he is aggressive, is unlikely to enjoy musicals, and would probably prefer beer over nimbu-paani (lemonade).

Even relatively important decisions are influenced by this tendency to make unwarranted assumptions based on a few cues.

Looking the part

In one recent study, subjects were asked to decide how much money to invest with an investment adviser based on photos and an ID. When the investment adviser wore a suit and had gone to a big-name school, subjects were willing to invest significantly more money than if the photo showed the same man in a T-shirt and khakis with a degree from a smaller school.

Interestingly, when the photo showed the man in a suit, people were also much less likely to check on the adviser’s credentials. We tend to put a lot of trust in people who look the part we want them to play.

The key to avoid being affected negatively by this effect is to pause whenever you think your decision may have the potential of being tainted by the fact that you may like the person concerned from another context or because of their other likeable traits.

When it comes to judging people endorsing products, step back and try determining if the person has the credentials to speak knowledgeably about the endorsed product. If not, then there is really no reason why their word should carry any special weight in influencing your decision.

Send your comments to driversseat@livemint.com

Praveen Aggarwal is an associate professor of marketing at the Labovitz School of Business & Economics at the University of Minnesota Duluth and Rajiv Vaidyanathan is a professor of marketing and director of MBA programmes at the University of Minnesota Duluth.

My Reads Logout