Author Malcolm Gladwell starts off Blink with one of his many anecdotes - and it is the anecdote that serves as one of his primary tools of argument (the other being scientific studies). It looks at the Getty Museum in Southern California, which bought what turned out to be a highly controversial piece of work called a kouros (a type of Greek sculpture from antiquity). It was arguably the most pristine of any one of its counterparts found, and was subjected to extensive geological tests. The tests confirmed its authenticity. However, when experts of the kouros had a first look at it, they almost immediately stated that it was a fake. How could it be that months of meticulous testing could be disaffirmed by a split-second judgment, albeit by experts?
This moment, or "blink", is what Gladwell focuses his argument on throughout the book. He first delves into the concept of "thin-slicing" - in which he argues that sometimes it is necessary only to have a small amount of information in order to make important, and also effective, decisions. Having certain expectations about any given situation based on very little information is much more common and widespread, in ways both good and bad, then people would like to think. What this means is that a context in which a person is observed can give vastly different types of information about that person than other, equally valid, contexts.
In the next part of the book, Gladwell looks at "snap judgments" and how thin-slicing information can lead people to make almost instantaneous decisions - whether it is a coach assessing their player's technique or a student taking a test. In light of a lack of information, people often unconsciously vigorously scan for information that their conscious mind cannot conceive of. This is where the subtle, and often invisible, perspectives, attitudes, and decisions that tend to be difficult to describe arise. A lack of information, Gladwell argues, is something that is not seen as appropriate in today's world, but often those with the best acumen in any given profession cannot completely explain their decisions.
Gladwell further looks at the discrepancy between stated conscious values and unconscious values. He provides the example of how US President Warren Harding came to power - largely based upon his “senatorial” and “stately” looks. Gladwell states that people found him to look and walk like a president, so their unconscious apparatuses came to accept him above other (possibly) more competent candidates. These biases are difficult to identify, says Gladwell, and even more difficult to admit. Such an argument posits that many decisions people make on a daily basis are a lot less likely based in reason and rationality than people would like to think.
Gladwell moves onto an even more complex situation concerning a former Marine named Paul Van Riper, who is asked by the US Military to play a Middle Eastern dictator gone rough in a war game that was conducted before the 2003 US invasion of Iraq. The team led by the military had every possible advantage over Riper’s team - tactical, weaponry, technology, and control over political and economic conditions. Nonetheless, Riper’s team managed to sink the opposing team's ships in a matter of a few hours - completely voiding the entire effort. This was because Riper used more traditional methods of communication (such as delivering messages through codes transported via a motorcycle) to make an attack. Gladwell uses this anecdote to illustrate Riper’s mix of instinctive and deliberate thinking, thus qualifying the overall claim of the book - that a mix of approaches is sometimes necessary for successful decision-making to happen.
Gladwell then looks at experts - and there is another qualification in his argument here. The skill and experience that experts have allow them to more clearly articulate unconscious decisions they make, because they have habituated the explanatory aspect of decision-making. However, this goes back to the fact that deliberate or delineated, careful thinking is necessary to make quick decisions - but expertise is necessary for explaining those decisions.
In the final chapter, Gladwell speaks of heightened sensitivity in high-stress situations. He cites police brutality, writing about an incident involving four officers who shot a man they believed was pulling a gun from his pocket. The officers fired a few dozen bullets at him, but then learned that the man was reaching for his wallet. They later recounted that they had little time to make coherent decisions.
Gladwell ends Blink with a short nod to classical music auditions and how the process has changed over time to create less bias amongst the judges; after the audition process was made more rigorous and less biased, the number of successful female applicants in America’s top symphonies skyrocketed. This alludes to the fact that judges could not be neutral in their judgments unless they were made unaware of the applicant's identity - another example of unconscious biases at work.