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.

January 11: Worst-case Scenario Day

On this day in 1964, the Surgeon General of the United States released the first report linking cigarette smoking with cancer. The report was based on over 7,000 articles that correlated smoking with disease.  Acting on the report’s findings, Congress acted, passing The Federal Cigarette Labeling and Advertising Act of 1965 which required cigarette packages to carry the following Surgeon General’s Warning:  “Caution: Cigarette Smoking May Be Hazardous to Your Health” (1).

Just as that first Surgeon General’s report on smoking caused Americans to consider the dangerous consequences of smoking, another event that happened on this day in 1918 led generations of people to apply prudent forethought when putting together a plan of action.

On January 11, 1918, Edward Aloysius Murphy, Jr. was born, the man behind Murphy’s Law, which reminds us that, “Anything that can go wrong will go wrong!”  

A graduate of the United States Military Academy at West Point, Murphy served as a pilot in World War II.  After the war, Murphy became an aerospace engineer, and in 1951 he was assisting U.S. Air Force scientists in California’s Mojave Desert where they were conducting tests to study the effects of the force of gravity on pilots.  To simulate the force of an airplane crash, the project team mounted a rocket sled on a half-mile track.  At first, the tests were conducted using a dummy, which was later replaced with a chimpanzee.  Then a physician named Colonel John Paul Stapp volunteered to ride the sled, nicknamed “Gee Whiz,” as it raced over 200 miles per hour across the desert floor and suddenly came to an abrupt stop.  

Murphy’s contribution to the experiment were sensors that were attached to Dr. Stapp to measure the G-force as the rocket sled braked.

Although Murphy’s name became attached to the law, the person credited with first uttering the law and spreading it was Dr. Stapp.  During a press conference after the tests, Stapp was asked how the team avoided any serious injuries during its experiments.  The doctor responded by saying that they were able to anticipate mistakes by applying Murphy’s Law: “If anything can go wrong, it will” (2).

Today’s Challenge:  Contingency Plans & Cautionary Notes

What are some mistakes you have made, some failures you have experienced, or some accidents you have been the victim of in your life so far? What specific advice would you give others to help them avoid these mistakes or accidents?  Write the text of a public service announcement (PSA) that focuses on a specific danger that might be avoided by exercising caution or by applying Murphy’s Law.  Give details on what specifically might go wrong as well as detailed steps on how to avoid it. (Common Core Writing 2 – Expository)

Quotation of the Day:  A thousand people will stop smoking today. Their funerals will be held sometime in the next three or four days.  -Surgeon General C. Everett Koop

1-Centers for Disease Control and Prevention. History of the Surgeon General’s Reports on Smoking and Health.

2-Hluchy, Patricia. The Man Behind Murphy’s Law.  Toronto Star. 11 Jan. 2009.