An experiment in diagnosis bias* was once conducted at MIT. A class had just been seated when a college representative walked in and explained that their professor was unavailable and a substitute instructor, one they had never met, would be taking the class, and that they would be asked to evaluate the instructor at the end of the class. To give them some background, they were given a very short bio. Unbeknownst to the students, half were given one bio, half a different one, BUT only two words were different:

Version #1:
Mr. ________ is a graduate student in the Department of Economics. He has had three semesters of teaching experience in psychology at another college. This is his first semester teaching Econ 701. He is 26 years old, a veteran, and married. People who know him consider him to be a very warm person, industrious, critical, practical, and determined.

Version #2:
Mr. ________ is a graduate student in the Department of Economics. He has had three semesters of teaching experience in psychology at another college. This is his first semester teaching Econ 701. He is 26 years old, a veteran, and married. People who know him consider him to be a rather cold person, industrious, critical, practical, and determined.

Each group received the same questionnaire at the end of the class, but you would have thought they were in different rooms. The group that received the “warm” bio loved the instructor, describing him as “good natured, considerate, informal, sociable, popular, humorous, and humane.”

The “cold” bio group, even though they had interacted with the exact same person, in the exact same room, at the same time described him as “self-centered, formal, unsociable, unpopular, irritable, humorless, and ruthless.”

Such is the power of our pre-judgments, our prejudices. It is frightening how quickly and easily they can form. Students at MIT may be young but they are rather smart, at least book smart. As a manager, as a leader, it is my duty to bring out the best in others, to develop them, to call out to their highest talents and abilities. Obviously, that requires that I keep an open mind, a beginner’s mind set.

It behooves us to be very aware of the power of words and the opinions of others in forming and shaping our judgments and prejudicing our evaluations. We are not always the independent free thinkers we like to believe we are. Forewarned should be forearmed.

*Diagnosis bias: Blindness to all evidence that contradicts our initial assessment of a person or situation.

Note: This story was drawn from “Sway: The Irresistible Pull of Irrational Behavior,” by Ori and Rom Brafman, p. 71, and contains direct quotes. The original study was titled The Warm-Cold Variable in First Impression of Persons, and was published in 1950 in the Journal of Personality 18, no. 4; pages 431 to 439.

This is a classic from the NSC Blog archive, originally posted June 25, 2008.