Subject:  Thin Slicing – The Warren Harding Effect (Halo Effect)

Event:  Publication of Malcolm Gladwell’s Blink, 2005

On January 11, 2005, Malcolm Gladwell published Blink, a book that examines the psychology of quick decision making. The book includes a fascinating critique of “thin-slicing,” the cognitive process of drawing broad, swift conclusions based on small bits of specific evidence.

While Gladwell explains that the type of intuitive judgment required for thin-slicing can be developed by experience and training, he also argues that it often leads to erroneous hasty generalizations based on prejudice and stereotypes.  

Warren G Harding-Harris & Ewing.jpg
Warren Harding (Library of Congress)

One specific cognitive bias that results from thin-slicing is illustrated by the biography of the 29th president of the United States, Warren G. Harding.  

Gladwell explains that there was nothing that distinguished Harding as a great leader or politician.  He was not highly intelligent, nor did he have any significant legislative or policy achievements.  From the beginning of his political career at the turn of the 19th century until his successful run for the U.S. presidency in 1921, besides winning elections, Harding accomplished little else.  Harding did have one thing that distinguished him, however — his regal appearance.  He was a handsome man with a rich, resonant voice.  

As Gladwell explains, it was Harding’s attractive appearance that short-circuited the public’s thinking:

Many people who looked at Warren Harding saw how extraordinarily handsome and distinguished-looking he was and jumped to the immediate — and entirely unwarranted — conclusion that he was a man of courage and intelligence and integrity.  They didn’t dig below the surface.  The way he looked carried so many powerful connotations that it stopped the normal process of thinking dead in its tracks (1).

What Gladwell calls the Warren Harding error is a more specific brand of a broader psychological phenomenon called the halo effect.  Anytime we allow a single quality, such as physical attractiveness, social status, or celebrity to overshadow all other qualities, we have fallen for the halo effect.  It explains why companies pay star athletes large sums of money to endorse their products.  Michael Jordan may not be an expert in car performance, but Chevrolet can count on the halo effect to subconsciously influence consumers.  Jordan’s athletic prowess is so prominent that it outshines all other qualities.

Recall, Retrieve, Recite, Ruminate, Reflect, Reason:  How can knowing the history of the 29th U.S. president help us avoid the halo effect and help us make better assessments of individuals?

Challenge –  Psychological Effect 101:  The Warren Harding error and the halo effect are just two examples of psychological effects that help us understand human thinking and behavior.  Research one of the effects below.  Then, write an elevator pitch explaining what the effect is and why it is important for better understanding the human species.

Barnum effect, Bystander effect, Contrast Effect, Cocktail party effect, Dunning-Kruger effect, Endowment effect, Framing Effect, False-consensus effect, Flynn Effect, Lake Wobegon Effect, Placebo Effect, Pratfall Effect


1-Gladwell, Malcolm. Blink:  The Power of Thinking Without Thinking.  New York:  Little, Brown and Company, 2005.