In Blink, Malcolm Gladwell explores the phenomenon he calls 'thin slicing'; the human ability to winnow out, in fractions of a second, salient facts from a mass of information and make a decision based on them. Something most of us do all the time without giving it much conscious thought - reading the facial expressions and body language of the people with whom we interact, walking down a busy street (or a quiet street late at night), our subconscious minds processing hundreds or even thousands of bits of information, deciding which few are important and making a judgement based on them. 
 Gladwell illustrates his thesis using several extended examples. The first is relatively straight forward. In 1983 California's Getty museum was offered a 2500 year old Greek statue, a kouros, for $10 million. All the tests said it was genuine but several art experts, at first glance and without being able to say precisely why, knew it was a fake. He also tells the stories of how an ugly chair conquered the offices of the world, how we are all effected by racial conditioning, how Chicago's Cook County hospital improved diagnosis of heart attacks by removing a physician's knowledge from the process, how a commander using WWII technology defeated the combined might of the the US armed forces in the largest ever war game, and more. 
 The author uses two main studies to demonstrate how this process of instant assessment works. John Gottman's 'love lab', where he gets couples to talk about a subject tangentially connected with their relationship and videos the exchange to bring out the non-verbal cues, and Paul Ekman, who is an expert of facial micro-expressions that last microseconds and over which we have no control (this latter also being the model for the excellent TV show Lie To Me with Tim Roth). Gladwell builds his argument convincingly and refers back to his examples frequently for both illustration and dramatic effect. Each example he uses shows a different facet of the Blink effect but also, and this is vital, how it can go wrong in certain circumstances. 
 While it is quick, this subconscious ability does require a moment to work, and can be short circuited by rushing or by an overload of adrenaline. Another case study chillingly shows what can happen when our subconscious is not given the opportunity to work properly. In 1999 an unarmed, innocent man, Amadou Diallo, was shot 41 times in the entryway of his own New York apartment building, by four policemen. He shows how a lack of experience, over-hasty action and perhaps even the over-confidence of numbers allowed these policemen to fall back on crude stereotypes and allow an initial poor assessment to lead them down a tragic course of events. 
 While Gladwell lauds the benefits of both listening to this subconscious supercomputer and developing the skills, in backing up the studies he constantly refers to the fact that this understanding has often been achieved by the exact opposite type of mentation - deliberate, analytical evaluation of evidence. This, along with the examples given, should show the reader that there are appropriate and inappropriate areas for this sort of thinking, although I can imagine some of the readership taking away only the face-value lesson of relying on first instincts and gut feelings. I would have liked to see a chapter on the abuse of these impressions, which is after all how con artists and frauds such as psychics operate. This could have been perhaps added into the chapter on Warren G. Harding, who was elected as US president because he was tall, handsome, masculine, dignified - and is considered by historians to be one of the worst presidents in US history. I want to take nothing away from this excellent book, however. It is superbly written, making excellent use of pacing and the storylines of the examples he uses to give the book structure. Malcolm Gladwell has a great style, authoritative and engaging, and he packs a great deal of both information and analysis into what is a quick, easy and enjoyable read.