April 12, 2005

Snap judgments

I just finished reading Malcolm Gladwell's book Blink. It deals with how we all make snap judgments about people and things, sometimes within a couple of seconds or less. Gladwell reports on a whole slew of studies that suggest that we have the ability to 'thin-slice' events, to make major conclusions from just a narrow window of observations.

I first read about this as applied to teaching in an essay by Gladwell that appeared in the New Yorker (May 29, 2000) where he described research by psychologists Nalini Ambady and Robert Rosenthal who found that by showing observers silent videoclips of teachers in action, the observers (who had never met the teachers before) were able to make judgments of teacher effectiveness that correlated strongly with the evaluations of students who had taken an entire course with that teacher. (Source: Half a Minute: Predicting Teacher Evaluations From Thin Slices of Nonverbal Behavior and Physical Attractiveness, Journal of Personality and Social Psychology, 1993, vol. 64, No. 3, 431-441.)

This result is enough to give any teacher the heebie-jeebies. The thought that students have formed stable and robust judgments about you before you have even opened your mouth on the very first day of the very first class is unnerving. It seems so unfair that you are being judged before you can even begin to prove yourself. But, for good or bad, this seems to be supported by other studies, such as those done by Robert Boice in his book Advice for New Faculty Members.

The implication for this is that the cliché "You never get a second chance to make a first impression" is all too true. And what Gladwell's New Yorker article and book seem to suggest is that this kind of thin-slicing is something that all of us do all the time. But not all of us do it well. Some people use thin-slicing to arrive at conclusions that are valid, others to arrive at completely erroneous judgments.

Those who do it well tend to be people who have considerable experience in that particular area. They have distilled that experience into some key variables that they then use to size up the situation at a glance, often without even consciously being aware of how they do it.

Seen in this way, the seemingly uncanny ability of people to identify at a glance who the good and bad teachers are might not seem that surprising. Most people have had lots of experience with many teachers in their lives, and along the way have unconsciously picked up subtle non-verbal cues that they use to correlate with good and bad teaching. They use these markers as predictors and seem to be quite good at it.

I was self-consciously reflecting on this last week when I ran two mock-seminars for visiting high-school seniors as part of "Experience Case " days. The idea was to have a seminar class for these students so that they could see what a seminar would be like if they chose to matriculate here. I found that just by glancing around the room at the assembled students at the beginning, I could tell who was likely to be an active participant in the seminar and who would not.

It was easy for me to make these predictions and I was pretty confident that I would be proven right, and I usually was. But how did I do it? Hard to tell. But I have taught for many years and encountered thousands of students and this wealth of experience undoubtedly played a role in my ability to make snap judgments. If pressed to explain my judgments I might say that it was the way the students sat, their body language, the way they made eye contact, the expression on their faces, and other things like that.

But while I am confident about my ability to predict the students' subsequent behavior in the seminar, I am not nearly as confident in the validity of the reasons I give. And this is consistent with what Gladwell reports in his book. Many of the experts who made good judgments did not know how they arrived at their conclusions or, when they did give reasons, the reasons could not stand up to close scrutiny.

He gives the example of veteran tennis pro and coach Vic Braden. Braden found that when watching tennis players about to make their second serve, he could predict with uncanny accuracy (close to 100%) when they would double fault. This is amazing because he was watching top players (who very rarely double fault) perform on television, and many of the players were people he had never seen play before. But what drove Braden crazy was that he could not say how he made his predictions. He just knew in a flash of insight that they would, and no amount of watching slow-motion replays enabled him to pinpoint the reasons.

But Gladwell points out that we use thin-slicing techniques even is situations where we do not have much experience or expertise and these judgments can lead us astray. In later postings, I will describe the kinds of situations where snap judgments are likely to lead us to shaky conclusions and where we should be alert.


Last Saturday, I went with a group of students from my SAGES class to see the Eldred production of Bertholt Brecht's play Life of Galileo The themes of the play are remarkably relevant for the present day, dealing with science-religion conflicts, politics in universities, and funding pressures. My SAGES course deals with the nature of scientific revolutions and the Copernican revolution is one of the key ones. But in addition to the scientific and political issues, the play also deals with the human side of Galileo.

There is one very minor character in the play called Clavius (described as the world's foremost mathematician) who is being played by a different Case faculty member each night. Last Saturday it was Arts and Sciences Dean Mark Turner. Next Saturday the 16th, I will be doing the cameo spot. I have to deliver just one line so don't blink, you might miss it!

The play is well worth seeing, See here for more details and show times.


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"You never get a second chance to make a first impression"

To an extent, you don't even get a first chance. :) People make snap judgments even before the subject has committed a single conscious action. I know, because I do it. The disturbing thing (at least to my analytic thinking) is that people are so very good at those judgments, like the tennis coach you describe. Sometimes you could spend hours analyzing things and come back to the conclusion that your snap decision was right all along. As someone who was subjected to innumerable multiple choice tests, (but not in your class! :) ) I'd often find that after 10 minutes of checking my work, the choice I picked on first glance was right.

As you point out, there's a balance. We should allow ourselves to make snap judgments and take advantage of our amazing sub-conscious, while allowing subsequent data to possibly contradict it.

I think there was a segment on NPR this morning about "how we make decisions" where they interviewed a pediatric neurosurgeon from Johns Hopkins.

Posted by Brian Moore on April 12, 2005 11:06 AM

Yes, coincidentally, NPR just today (in the 7:50-8:00am time slot) started a series on the topic of making judgments.

I am curious to see what they will discuss in the future segments and how they will compare with my series of posts.

Posted by Mano Singham on April 12, 2005 03:06 PM

I look forward to this series. The "how" of it is a big question. I suppose the cognitive folks would know more, but when we make these judgments, I'd have to imagine it is similar to what you describe; that we pick up on a number of visual and audio clues, then our brain matches them to previously observed behavior. Perhaps it is similar to the way the FBI profiles criminals, but on a more thorough, in-depth and accurate level? Astounding though how rapidly the brain can process the data.

Yet the idea that these judgments are accurate make sense. When I was little my mom always told me I was a great judge of character. I would usually know immediately upon meeting someone if they were someone trustworthy, friendly, fun, smart, stable, or whatever. But with time I came to doubt, to question my insta-decision and to give people more opportunity. And yet, like Brian with his tests, the first instinct was right. I think I learned to doubt because the instant-judgment seemed more like a hunch or feeling and less of a well-reasoned logical decision. Also my hunch was not always in keeping with the opinions of others who may have known more about the person in question. But with you pointing out these studies, I wonder, about these hunches. I would not be surprised if our insta-judgments are very rational and orderly. Perhaps they just happen so swiftly we are just not consciously aware that we are making rational choices based on empirical evidence.

Posted by cool on April 12, 2005 05:36 PM


In his New Yorker article, Gladwell says that when the observers of teachers were given distracting tasks (such as memorizing numbers) while watching the tapes, their snap judgments were not affected. But when they asked to think hard about their ratings before making them, the acccuracy of their ratings suffered.

Gladwell concludes "Thinking only gets in the way." So our subconscious insta-judgmets could well be more rational and reliable than our conscious judgments.

But it is still weird and somehow disturbing to me. I don't know why...

Posted by Mano Singham on April 12, 2005 06:17 PM

It is wierd, a little eerie, but also sort of cool. It seems like these run like background processes in a computer program, but if you interrupt the process it becomes corrupted.

I wonder historically if this ability to insta-judge effectively may have sometimes been taken to mean that a particular person was not just intuitive, but perhaps a bit psychic. Yet, rather than using "supernatural" powers these people have been both observant (to build up their databases) and willing to rely on their rational instinct.

Posted by Heidi Cool on April 13, 2005 11:10 AM