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the halo effect

The halo effect refers to a bias whereby the perception of a positive trait in a person or product positively influences further judgments about traits of that person or products by the same manufacturer. One of the more common halo effects is the judgment that a good looking person is intelligent and amiable.

There is also a reverse halo effect whereby perception of a negative or undesirable trait in individuals, brands, or other things influences further negative judgments about the traits of that individual, brand, etc. If a person "looks evil" or "looks guilty" you may judge anything he says or does with suspicion; eventually you may feel confident that you have confirmed your first impression with solid evidence when, in fact, your evidence is completely tainted and conditioned by your first impression. The hope that the halo effect will influence a judge or jury is one reason some criminal lawyers might like their clients to be clean-shaven and dressed neatly when they appear at trial.

The phrase was coined by psychologist Edward Thorndike in 1920 to describe the way commanding officers rated their soldiers. He found that officers usually judged their men as being either good or bad "right across the board. There was little mixing of traits; few people were said to be good in one respect but bad in another."* The old saying that first impressions make lasting impressions is at the heart of the halo effect. If a soldier made a good (or bad) first impression on his commanding officer, that impression would influence the officer's judgment of future behavior. It is  very unlikely that given a group of soldiers every one of them would be totally good or totally bad at everything, but the evaluations seemed to indicate that this was the case. More likely, however, the earlier perceptions either positively or negatively affected those later perceptions and judgments.

The halo effect seems to ride on the coattails of confirmation bias: once we've made a judgment about positive or negative traits, that judgment influences future perceptions so that they confirm our initial judgment.

Some researchers have found evidence that student evaluations of their college instructors are formed and remain stable after only a few minutes or hours in class.  If a student evaluated a teacher highly early on in the course, he or she was likely to rank the teacher highly at the end of the course. Unfortunately, for those teachers who made bad first impressions on the students, their performance over the course of the term would be largely irrelevant to how they would be perceived by their students. Some might think this shows how wonderful intuition is: students can perceive how good a teacher is within minutes or days of meeting her. On the other hand, the halo effect may be at work here. Also, the fact that the evaluations are similar at the beginning and end of the semester might indicate that there is something seriously wrong with the typical evaluation form. It may be measuring little more than likeability and the halo effect.

In The Halo Effect: ... and the Eight Other Business Delusions That Deceive Managers (Free Press 2009), Phil Rosenzweig writes:

Much of our thinking about company performance is shaped by the halo effect … when a company is growing and profitable, we tend to infer that it has a brilliant strategy, a visionary CEO, motivated people, and a vibrant culture. When performance falters, we’re quick to say the strategy was misguided, the CEO became arrogant, the people were complacent, and the culture stodgy … At first, all of this may seem like harmless journalistic hyperbole, but when researchers gather data that are contaminated by the halo effect – including not only press accounts but interviews with managers – the findings are suspect. That is the principal flaw in the research of Jim Collins’s Good to Great, Collins and Porras’s Built to Last, and many other studies going back to Peters and Waterman’s In Search of Excellence. They claim to have identified the drivers of company performance, but they have mainly shown the way that high performers are described.

The fact is, despite the success of books like From Good to Great, it is not logically justifiable to infer the goodness (or badness) of a company's strategy, values, or leadership based on the fact of the success or failure of the company. The reason is obvious. Many companies go from good to bad and don't change their strategy or their leadership. But there is a natural bias to attribute good qualities to management and leadership when a company is successful and to attribute bad qualities to management and leadership when a company is failing.

When the athletic team succeeds or fails, the coach is often assumed to be a genius or an idiot, but the same coach doing the same things year in and year out has some successful years and some years that are failures. Yet, many people are quick to give credit for the success of a team to the coach when the team wins, conveniently forgetting that the same coach led the team to a fifth place finish last year. The success or failure of the team leads many people to perceive qualities in the coach and his strategy, plan, preparation, work ethic, etc. One finds similar comments from TV golf announcers about various golf coaches. If a coach has several players who win tournaments or play well during a relatively short period of time, the coach is a genius. When his players fire him or quit winning, the same coach's methods are archaic and outdated, not suitable for the modern game.

Ronald Reagan was sometimes called the Teflon President, but he might more accurately have been called the Halo Effect President. The man had very few qualities that qualified him to be the leader of the free world, but he was the most likeable man on the planet. He exuded confidence and steadfastness as the good guy in the white hat. He was the John Wayne of politics. He could also be self-effacing when it suited him and his ability to deliver a story or a joke was second to none. He had little difficulty giving the impression that he knew what he was talking about when he told us that trees cause more pollution than automobiles or that government is the cause of all our problems. The public had little problem excusing the fact that while he was president Oliver North was selling arms to Iran and using the money to fund a group of terrorists...excuse me...freedom fighters in Nicaragua, unbeknownst to Congress or the American people. Reagan had a great sense of humor and you felt you could trust him with your only offspring and he wouldn't cheat you at cards. But his reputation for being a great leader is mainly conditioned by his personality, his great speech writers, and the "lamestream media." When people long for a leader like Reagan to reappear what they are really longing for is an actor who could put anyone at ease with his perceived authority, honesty, confident manner, wry smile, and his incomparable sense of humor.

Barack Obama benefited tremendously from the halo effect in his 2008 election campaign for president. His powerful speaking ability and the fact that he's highly educated and appears physically fit (though I understand he's a smoker) led many people to assume he possesses many other fine qualities that would qualify him to be leader of the free world. The fact is that Mr. Obama had very little experience that would qualify him to be president of the United States. He was helped significantly, of course, in his election bid when his opponent, John McCain, chose Sarah Palin for a running mate, thereby undermining one of the main themes of his campaign: country first. There is little doubt that Sen. McCain has the right stuff to be president, but if there was anyone less qualified to be president than Mr. Obama, it was surely Ms. Palin. (She wasn't running for president, of course, but if McCain died in office, she would have become leader of the free world....a frightening thought, indeed.)

Anyway, it appears the Founders didn't think it would be too hard to be president since the only job qualifications are being born here at least thirty-five years before becoming president and living here for fourteen years. That's right. Most adults in this country meet the minimum qualifications to be president. That's comforting.

In 1977, social psychologists Richard Nisbett and Timothy Wilson published "The halo effect: Evidence for unconscious alteration of judgments." This was a study on our lack of awareness of the influence on our thinking of the halo effect.

Students were told the research was investigating teacher evaluations. Specifically, they were told, the experimenters were interested in whether judgements varied depending on the amount of exposure students had to a particular lecturer. This was a total lie.

In fact the students had been divided into two groups who were going to watch two different videos of the same lecturer, who happened to have a strong Belgian accent (this is relevant!). One group watched the lecturer answer a series of questions in an extremely warm and friendly manner. The second group saw exactly the same person answer exactly the [same] questions in a cold and distant manner. Experimenters made sure it was obvious which of the lecturers alter-egos was more likeable. In one he appeared to like teaching and students and in the other he came across as a much more authoritarian figure who didn't like teaching at all.

After each group of students watched the videos, they were asked to rate the lecturer on physical appearance, mannerisms and even his accent (mannerisms were kept the same across both videos). Consistent with the halo effect, students who saw the 'warm' incarnation of the lecturer rated him more attractive, his mannerisms more likeable and even his accent as more appealing. This was unsurprising, as it backed up previous work on the halo effect.*

What was most interesting about this study is that the students believed that they had not been influenced by the likeability of the teacher in their global evaluations. The students were convinced that their global evaluations had influenced their liking or disliking the teacher.

The halo effect is at work when we buy a product because it was made by a company that makes something else that we believe is a good product. We seem to assume that if a company made a good product, the company must have many good qualities that will lead it to produce more good products. Many of us know from experience that this isn't true. KitchenAid might make a fine dishwasher but it makes a crappy can opener. (My experience was with the can opener first. I wouldn't even consider a KitchenAid dishwasher when my wife and I were in the market for one, but the fact is that there need be no necessary connection between their crummy can opener and their dishwasher.)

Advertisers take advantage of the halo effect when they hire famous people or beautiful people to sell their products. The advertisers are banking on the consumer's tendency to judge the product favorably because they judge the actor or beautiful actress favorably.

James Randi took advantage of the halo effect when he tested two Russian ladies who claimed to be able to use their psychic powers to determine the personality and life experiences of someone from a photograph. He showed the ladies a picture of Ted Bundy, a handsome, wholesome-looking mass murderer. The results are both amusing and disgusting. See for yourself:

Finally, consider this:

A growing literature suggests that the halo effect may also apply to foods, and ultimately influence what and how much we eat. For instance, research has shown that people tend to consume more calories at fast-food restaurants claiming to serve "healthier" foods, compared to the amount they eat at a typical burger-and-fry joint. The reasoning is that when people perceive a food to be more nutritious, they tend to let their guard down when it comes to being careful about counting calories -- ultimately leading them to overeat or feel entitled to indulge. This health halo effect also seems to apply to certain foods considered by many to be especially healthy, such as organic products. Specifically, some people mistakenly assume that these foods are more nutritious just because they carry an "organic" label -an area of longstanding active debate among food and nutrition scientists.

I can't attest to how fast or large this "growing literature" is, but there has been one study where the subjects were all given organic food, although some was labeled non-organic. The participants found the "organic" food tastier, less fatty, lower in calories, higher in fiber, and more nutritious than the "non-organic" food.*

And the food labeled non-organic didn't even glow in the dark.

See also the hidden persuaders.

further reading

books and articles

Adams, James L. Conceptual Blockbusting: A Guide to Better Ideas 3rd ed. (Perseus Press, 1990).

Alcock, J. (1995) "The Belief Engine," Skeptical Inquirer. 19(3): 255-263.

Alcock, James E. Science and Supernature : a Critical Appraisal of Parapsychology (Buffalo, N.Y.: Prometheus Books, 1990).

Ariely, Dan.  (2008). Predictably Irrational: The Hidden Forces That Shape Our Decisions (HarperCollins).

Bausell, R. Barker. (2007). Snake Oil Science: The Truth about Complementary and Alternative Medicine Oxford.

Browne, M. Neil & Stuart M. Keeley. Asking the Right Questions: A Guide to Critical Thinking (Prentice Hall, 1997).

Burton, Robert. 2008. On Being Certain: Believing You Are Right Even When You're Not. St. Martin's Press.

Carroll, Robert Todd. Becoming a Critical Thinker - A Guide for the New Millennium (Boston: Pearson Custom Publishing, 2000).

Chabris, Christopher and Daniel Simons. 2010. The Invisible Gorilla: And Other Ways Our Intuitions Deceive Us. Crown.

Damer. T. Edward. Attacking Faulty Reasoning: A Practical Guide to Fallacy-Free Arguments 4th edition (Wadsworth Pub Co, 2001).

Dawes, Robyn M. Everyday Irrationality: How Pseudo-Scientists, Lunatics, and the Rest of Us Systematically Fail to Think Rationally (Westview Press 2003).

Dean, Geoffrey and Ivan Kelly. "Is Astrology Relevant to Consciousness and Psi? Journal of Consciousness Studies. Volume 10, No. 6-7, June-July 2003.

Dean, Geoffrey, Ivan W. Kelly, and Arthur Mather. "Undeceiving Ourselves," in The Skeptic Encyclopedia of Pseudoscience, eds. Michael Shermer and Pat Linse (ABC-CLIO 2002).

Frazier, Kendrick, ed. Paranormal Borderlands of Science (Amherst, N.Y.: Prometheus Books, 1991).

Gardner, Martin. Fads and Fallacies in the Name of Science (New York: Dover Publications, Inc., 1957), 

Gardner, Martin. Science: Good, Bad and Bogus (Buffalo, N.Y.: Prometheus Books, 1981).

Giere, Ronald, Understanding Scientific Reasoning, 4th ed, (New York, Holt Rinehart, Winston: 1998).

Gilovich, Thomas. How We Know What Isn't So: The Fallibility of Human Reason in Everyday Life (New York: The Free Press, 1993).

Groopman, Jerome. M.D. 2007. How Doctors Think. Houghton Mifflin. My review of this book is here.

Hall, Harriet A. "Wired to the Kitchen Sink - Studying Weird Claims for Fun and Profit," Skeptical Inquirer. May/June 2003.

Hines, Terence. "A Clear, Sharp View of the Fuzzy Inkblot Test," Skeptical Inquirer, September/October 2003. (A review of What's Wrong with the Rorschach? by James M. Wood, M. Teresa Nezworski, Scott O. Lilienfeld, and Howard N. Garb (Jossey-Bass 2003).

Hines, Terence. Pseudoscience and the Paranormal (Buffalo, NY: Prometheus Books, 2003).

Hyman, Ray. The Elusive Quarry : a Scientific Appraisal of Psychical Research (Buffalo, N.Y.: Prometheus Books, 1989).

Hyman Ray. "Why and When Are Smart People Stupid?" in Sternberg 2002.

Kahneman, Daniel. Paul Slovic, and Amos Tversky.eds. 1982. Judgment Under Uncertainty: Heuristics and Biases Cambridge University Press.

Kahane, Howard. Logic and Contemporary Rhetoric: The Use of Reason in Everyday Life, 8th edition(Wadsworth, 1997).

Kahneman, Daniel. Thinking, Fast and Slow (Kindle 2011) . Book review.

Kida, Thomas. 2006. Don't Believe Everything You Think: The 6 Basic Mistakes We Make in Thinking. Prometheus.

Kourany, Janet A. Scientific Knowledge: Basic Issues in the Philosophy of Science, 2nd edition (Belmont: Wadsworth Publishing Co., 1998).

Levine, Robert. 2003. The Power of Persuasion - How We're Bought and Sold. John Wiley & Sons.

Moore, Brooke Noel. Critical Thinking (Mayfield Publishing Company, 2000).

Neher, Andrew. The Psychology of Transcendence  (Prentice-Hall 1980).

Park, Robert L. Voodoo Science: the Road from Foolishness to Fraud (Oxford University Press, 2000).

Pickover, Clifford A. The Girl Who Gave Birth to Rabbits : A True Medical Mystery (Prometheus, 2000).

Randi, James. Flim-Flam! Psychics, ESP, Unicorns, and Other Delusions (Buffalo, New York: Prometheus Books, 1982).

Reed, Graham. The Psychology of Anomalous Experience : A Cognitive Approach (Buffalo, NY: Prometheus Books, 1988).

Sagan, Carl. The Demon-Haunted World - Science as a Candle in the Dark (New York: Random House, 1995).

Schick, Jr., Theodore and Lewis Vaughn, How to Think About Weird Things 5th ed. (McGraw-Hill, 2001), 

Seckel, Al. (2006). Incredible Visual Illusions. Arcturus Publishing, Ltd.

Shermer, Michael. The Borderlands of Science: Where Sense Meets Nonsense (Oxford University Press, 2001).

Shermer, Michael. Why People Believe Weird Things: Pseudoscience, Superstition, and Other Confusions of Our Time 2nd revised edition (Owl Books 2002).

Shermer, Michael. "Why Smart People Believe Weird Things," Skeptic. Vol. 10 No. 2, 2003, pp. 62-73.

Skinner, B. F. 'Superstition' in the Pigeon. Indiana University First published in Journal of Experimental Psychology, 38, 168-172.

Stanovich, Keith E., How to Think Straight About Psychology, 5th edition (Addison-Wesley, 1997).

Stenger, Victor J. Physics and Psychics: the Search for a World Beyond the Senses (Buffalo, N.Y.: Prometheus Books, 1990).

Sternberg, Robert J. ed. Why Smart people Can Be So Stupid. (Yale University Press 2002).

Sutherland, Stuart. (2007). Irrationality. 2rev edition (Pinter & Martin Ltd).

Taleb, Nassim Nicholas. 2007.  The Black Swan: The Impact of the Highly Improbable. Random House.

Van Hecke, Madeleine L. (2007). Blind Spots: Why Smart People Do Dumb Things. Prometheus.

Vaughn, Lewis. 2007. The Power of Critical Thinking: Effective Reasoning About Ordinary and Extraordinary Claims. 2nd. ed. Oxford University Press.

Vyse, Stuart A. Believing in Magic: The Psychology of Superstition (Oxford University Press 2000).

Wiseman, Richard. Deception & Self-Deception: Investigating Psychics (Prometheus Books, 1997).

Zusne, Leonard & Warren Jones. Anomalistic Psychology: A Study of Magical Thinking (Lawrence Erlbaum Association, 1990).


Unnatural Acts: A follow-up to my book Unnatural Acts: Critical Thinking, Skepticism and Science Exposed! The blog offers irregular postings about biases, fallacies, and illusions.

A Visual Study Guide to Cognitive Biases Eric Fernandez

You're Not So Smart David McRaney

Last updated 14-Jan-2014

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