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Likability is Not a Substitute for Credibility

My mother used to read bedtime stories to me when I was young. While she read the usual children’s books of the day, she also sprinkled in a good dose of folklore, fairy tales, and mythology. I was particularly fascinated by Greek mythology and have kept that interest up over the years. Recently, I reread the story of the god Apollo who was so infatuated by the priestess Cassandra that he gave her the ability to see the future to gain favor with her. However, when she didn’t return that favor, he could not revoke the gift of foresight, but he could nullify it by cursing her so that no one would believe her.

You might think it would be difficult to manipulate people so that they don’t believe someone who is consistently right, but it actually isn’t all that hard. All you have to do is change the perceived credibility of a person by making them unlikable.

Research by Pilditch, Madsen, and Custer (published in the National Library of Medicine) explained, there are “…two main routes to determine veracity; the perceived credibility of the source, and direct evaluation via first-hand evidence, i.e. testing the advice against observation.” Their overwhelming conclusion was that the veracity of information is “…interpreted in light of the perceived credibility of the source, such that beliefs from high trust sources are taken up, whilst beliefs from low trust sources are treated with suspicion and potentially rejected…” And once a source is perceived as credible (or not credible) it is difficult to change that perception. As the researchers discovered, “…sources accompanied by a high trust cue not only get away with communicating falsehoods, but see their perceived credibility increase, whilst sources accompanied by low trust cues not only have truthful communications rejected, but have their low trust penalized even further.”

The reason for this odd outcome is because we perceive credibility emotionally, instead of factually. According to Professor Isabelle Jia of Claremont Colleges, there are “…two main components [of credibility]: 1) expertise and 2) trustworthiness.” However, there is a third factor “…related to credibility, likability…” And while it “…is not considered to be a component of credibility…” likability is a factor that significantly influences our perception of a person’s credibility. As a matter of fact, Robert V. Levine in Persuasion: So Easily Fooled emphasizes that “More than any single quality, we trust people we like.”

I first became aware of the power of likability from “Thinking, Fast and Slow.” Daniel Kahneman writes that “…when faced with a difficult question, we often answer an easier one instead, usually without noticing the substitution.” So, when an executive was asked the difficult question (should I invest in Ford stock?), “…the answer to an easier and related question (do I like Ford cars?) came readily to his mind and determined his choice.” Similarly, when evaluating the ability of experts, we subconsciously substitute likeability for credibility, because it is so much easier than finding answers to questions about expertise and trustworthiness. What’s even more alarming, says Philip Tetlock (an expert on experts), is we “…don’t demand evidence of accuracy [from trusted experts] …Accuracy is seldom determined after the fact and is almost never done with sufficient regularity and rigor that conclusions can be drawn.”

Politicians know what Apollo knew, we don’t believe people we don’t like, which is why negative campaigning is so pervasive. Conversely, advertisers are aware that we trust people we do like. In other words, we judge the messenger instead of the message and we judge the messenger on the wrong criteria. As a fiduciary (or other times good judgment is needed), I can’t substitute likes for observable evidence. I need to diligently evaluate the veracity of information I use and the credibility of experts I trust, instead of accepting or rejecting messages and messengers based on likes and dislikes. By the way, the likeability bias is a curse we all share. It’s not avoidable, but it is manageable if we’re aware of it.