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Can You Know Someone — or Some Place — in 2 Seconds?

In 1993, the brilliant Nalini Ambady, together with Robert Rosenthal (my advisor at Harvard, most famous for his research showing how teacher’s expectations influence students’ performance), published a startling finding: Students seem to be able to size up a professor in 2 seconds.

In their research, they first showed students 30-second video clips (with no sound) of professors teaching. The students, who had never met the teachers, reported their impressions of the teachers’ qualities such as competence, honesty, likability, confidence, and professionalism. Then they looked at the relationship between those snap judgments based on “thin slices” of behavior and the evaluations of students who had sat through an entire course with the professors. The two assessments – from 30 seconds and from an entire semester – were very similar.

Then Ambady and Rosenthal made the snap judgment even snappier, reducing the video clips from 30 seconds to 9 seconds, then 6, then 2. Even with just two seconds of the professors’ behavior to judge, those fleeting first impressions were correlated with students’ impressions based on an entire semester in class with the professors.

Those findings sparked probably hundreds of future investigations, still ongoing, of the processes by which all this happens and the limitations. Malcolm Gladwell turned the social psychologists’ research into publishing gold in his book Blink: The Power of Thinking Without Thinking.

I’ve been thinking about this research lately as I was looking for a new place to live. My rent went up in my previous place, where I lived for nearly 14 years, and my income did not, so off I went, deep into the rental listings. (I owned a home when I lived in Virginia, but can’t afford that here in Southern California.)

Rental listings can be amazing these days, complete with lots of high-quality pictures. I often thought I knew if I’d like a place just by clicking through all the images. Then I would show up and know in an instant – yes, probably 2 seconds – whether the place was right for me. I found the process especially intriguing when my guesses based on the online pictures were wrong. I’d get to the place in person and could see where all the pictures were from. The pictures were not misleading. But somehow, standing in the house in person, I knew immediately that the place that looked so right online, just wasn’t right for me.

So now I wonder about snap judgments of houses and places and other things other than people. With people, the research suggests that snap judgments work – when they do work, which is not always – largely because of the information available in nonverbal cues. But if we also make quick – and sometimes very accurate – judgments of things, what are we going by in those instances? If there is any systematic research on those questions, I don’t know about it.

If you are interested, here’s how my personal house-hunting story ended: I looked at places from about 10 miles south of where I was to more than 20 miles north, and ended up…in a small house, just a half-block away from where I was! So I am still in the tiny, funky, aptly-named town of Summerland, California.

Can You Know Someone — or Some Place — in 2 Seconds?

Bella DePaulo, Ph.D

Bella DePaulo (Ph.D., Harvard; Academic Affiliate, Psychological and Brain Sciences, UC Santa Barbara), an expert on single life, is the author of several books, including "Singled Out: How Singles Are Stereotyped, Stigmatized, and Ignored, and Still Live Happily Ever After" and "How We Live Now: Redefining Home and Family in the 21st Century." Her TEDx talk is "What no one ever told you about people who are single," Dr. DePaulo has discussed singles and single life on radio and television, including NPR and CNN, and her work has been described in newspapers such as the New York Times, the Washington Post, the Wall Street Journal, and USA Today, and magazines such as Time, Atlantic, the Week, More, the Nation, Business Week, AARP Magazine, and Newsweek. Dr. DePaulo is in her sixties. She has always been single and always will be. She is "single at heart" -- single is how she lives her best and most meaningful life. Visit her website at

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APA Reference
DePaulo, B. (2014). Can You Know Someone — or Some Place — in 2 Seconds?. Psych Central. Retrieved on April 3, 2020, from


Last updated: 11 Apr 2014
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