Blink is about rapid cognition, the sort of snap decision-making performed without thinking about how one is thinking, faster and often more correctly than the logical part of the brain can manage. Gladwell campaigns for snap judgments and mind reading with a gift for translating research into splendid storytelling. Building his case with scenes from a marriage, heart attack triage, speed dating, choking on the tennis court, selling cars, and military maneuvers, he persuades readers to think small and focus on the meaning of "thin slices" of behavior. The key is to rely on our adaptive unconscious, that provides us with instant and sophisticated information to warn of danger, read a stranger, or react to a new idea. Gladwell's conclusion, after studying how people make instant decisions in a wide range of fields from psychology to police work, is that we can make better instant judgments by training our mind and senses to focus on the most relevant facts—and that less input, as long as it's the right input, is better than more.
Gladwell is also careful to examine the flip side of this phenomenon: the times when "thin slicing" misleads us or gives us the wrong results. For instance, he presents examples where the mind works based on biases that don't necessarily enter the realm of conscious thought, but are nevertheless there, such as age, race, and height. The secret is knowing which information to discard and which to keep. Our brains are able to perform that work unconsciously; when rapid cognition breaks down, the brain has seized upon a more obvious but less correct predictor. Gladwell examines how race and gender affect car dealers' sales strategy, the effect of height on salary and promotion to top corporate positions, and unjustified police shootings of civilians to demonstrate that our unconscious biases have genuine and sometimes tragic consequences. He also examines how the wrong thin slice, in focus groups or in a single-sip test of soft drinks, can lead businesses to mistake consumer preferences.
Throughout the book, Gladwell introduces us to many people, and their stories and experiences of snap decisions. He has a talent for bringing these narratives to life, almost like a novel, and not only does he make these examples interesting and personal, but he keeps coming back to the handful that he has selected to incorporate into Blink. This makes it mush easier to follow what he is saying, having been introduced to the story already, and it keeps a clutter of examples from fogging up your mind.