Before you can say 

"The Tipping Point" was a small book, just a couple hundred pages, but its success was built on Gladwell's clever repetition of a few well-chosen words and phrases that seemed, from the moment you read them, destined to enter the culture -- not just the titular phrase but also the names for concepts, like "stickiness," or the titles he assigned to the key characters in his tale, the Connectors, Mavens and Salesmen. (Gladwell is also generally credited with coining the word "coolhunter," and the "broken windows" theory of crime fighting, while not his coinage, was certainly popularized in "The Tipping Point.")

He repeats this technique in "Blink" (also quite small), creating an entire nomenclature to describe the intricacies of rapid cognition. We get, first, "thin-slicing" -- "the ability of our unconscious to find patterns in situations and behavior based on very narrow slices of experience." By thin-slicing, our minds can just know; we can look at a situation, gather its essence in a few seconds or so, and extract meaning, order and truth amid the chaos of the moment. The first time he met Tom Hanks, Hollywood producer Brian Grazer tells Gladwell, he instantly knew the actor was different from others he'd seen. "We read hundreds of people for the part [in "Splash"], and other people were funnier than him. But they weren't as likable as him. I felt like I could live inside of him. I felt like his problems were problems I could relate to." And really, isn't this how most of us feel about Hanks? "If I asked you what he was like, you would say that he is decent and trustworthy and down-to-earth and funny," Gladwell writes. We like Hanks even though we don't know him, even though we've seen him only in the movies, playing many different people. He seems likable to us because we've sized him up -- we've thin-sliced.

We do this all the time in our interactions with others; people are constantly giving off signs about their personalities or their feelings, and we're constantly interpreting those signs, even if we're not aware of them. But making ourselves aware of them, Gladwell argues, can make things interesting. He cites a number of psychological studies that prove the power of thin-slicing. Want to know a doctor's likelihood of being sued for malpractice? No need to look at the doctor's professional history, or how well the doctor did in school, or what tests and procedures the doctor administers to patients. Just pay attention to how the doctor talks to patients, whether he or she is attentive. (More attentive doctors are less likely to be sued.) Want to know if a couple will stay together or break up? A good way to find out is by paying attention to how they interact with each other. If one partner shows contempt for the other -- defined by one psychologist as statements that "try to put that person on a lower plane than you," for instance, "You're scum" or "You are a bitch" -- then the relationship is probably not going to last.

But what if we can't quite figure out the secret to how we thin-slice certain situations -- what if we can't determine why we like Tom Hanks or, for that matter, anyone else? Well, we have to find a way to look behind what Gladwell calls the "locked door" of our subconscious, and we also have to make sure that we don't have a "storytelling problem," a mismatch between our explanation of how we're sizing up a situation and how we're actually sizing it up. We need to think about the "Warren Harding Error" -- the "dark side of rapid cognition," the moments when snap judgments can "lead us astray." (He calls it the "Warren Harding Error" for the mistake the nation made in 1920, when it elected a pretty awful president just because he seemed presidential.)

Gladwell has some fascinating insights into this dark side, and his section on the implicit association test -- a psychological tool that determines your unconscious, "automatic" preferences for certain kinds of people by measuring how long it takes you to assign words and faces to categories -- is the best part of the book. You can take the IAT here, but be careful. The unconscious is a mysterious thing, and don't be surprised if your test shows you to have an automatic preference for white people over black people, or for thin people over fat people, or for young people over old people. I grew up in apartheid South Africa and consider myself, as most people do, exceedingly egalitarian in how I treat people, but, I'm ashamed to say, my test showed an automatic preference for whites over blacks. Gladwell, who is half-black, found a similar preference when he took the test. Indeed, he notes, of the 50,000 African-Americans who've taken the race IAT, half show an automatic preference for whites.

This doesn't mean that Gladwell (or others, like me, who show a preference for whites) is racist. It just means that when he meets a black person, his brain makes a snap judgment; it forms an instant opinion, and the opinion it forms is lower than the opinion his brain forms of white people. And these instant opinions do affect the way we interact with people, Gladwell writes. If your unconscious has an automatic preference for white people and a black person comes to you for a job interview, "chances are you'll lean forward a little less, turn away slightly from him or her, close your body a bit, be a bit less expressive, maintain less eye contact, stand a little farther away, smile a lot less, hesitate and stumble over your words a bit more, laugh at jokes a bit less."

You'll do this without even knowing you're doing it, Gladwell says. And the person you're interviewing will come to a snap judgment about the way you're acting, and so he or she will act less confident and come off as unfriendly. And then your unconscious will pick up on the person's lack of confidence and come to the conclusion that he or she is not right for the job. "What this unconscious first impression will do, in other words, is throw the interview hopelessly off course."

Next Page: Clearly Gladwell doesn't mean to be useful, only interesting

• View blog reactions