Skip to Content

Book Summary: Blink – The Power of Thinking Without Thinking

Have you ever wondered how you make decisions in the blink of an eye? We all possess an incredible power that allows us to think without thinking. This intuition is often considered less reliable than logic, but Malcolm Gladwell offers real-world examples to prove otherwise. In this book summary, you’ll learn how trustworthy your snap-judgments truly are and how to value your unconscious ideas.

Often, the best decisions are the ones you can’t even explain.


  • Want to know the psychology behind first impressions
  • Don’t understand consumer choices
  • Require quick decision-making skills
  • Want to make better decisions in stressful situations


Our minds have two distinct ways of reaching conclusions. One is conscious and logical. We gather information and choose a certain path. But the other is unconscious. It happens quickly, often before we have time to think.

Book Summary: Blink - The Power of Thinking Without Thinking

The unconscious part of the mind is constantly scanning and processing everything so that we can function. If we had to thoughtfully consider every detail around us, life would be a lot more dangerous and exhausting.

We are trained to trust our logical conscious more. However, there is power and value in our unconscious snap-judgments.

Often, our unconscious can make even better decisions than our conscious ever could.

The Secret Life of Snap Decisions

We all make snap decisions. Which apple should you pick at the supermarket? Sure, some are bruised, but many are in great shape — why pick that one in particular?

Our minds are equipped with two thought processes: the conscious and the unconscious. Our conscious thoughts are rational; we can easily explain why we do or feel certain things. But our unconscious processes are hidden behind a locked door; we aren’t really sure why we make some snap decisions.

This conclusion doesn’t satisfy most people, and we feel a societal pressure to explain what is often unexplainable.

Without realizing it, we are constantly being primed by the things around us. Our subconscious is scanning every situation and taking note of the important bits so that it can guide us toward appropriate responses. The strong effects of priming were highlighted in an experiment conducted by psychologist John Bargh.

Bargh gathered a group of students and gave each one a word puzzle. Half of the puzzles were sprinkled with words associated with aggression, such as “rude” or “bold.” The other puzzles had more positive words, like “respect” or “polite.” All of the puzzles contained enough words to make the students unaware of any theme. They did not know they were being primed.

After completing the puzzles, the students were told to find a certain professor and ask about their next assignment. But, Bargh had prearranged it so that the professor would be engaged in a conversation when each student approached him. The goal was to see how the different puzzles affected the students’ likelihood to interrupt the professor’s prearranged conversation before 10 minutes had passed.

To Bargh’s intrigue, all of the students who had completed a “negative puzzle” interrupted within five minutes, but over 80% of the students with a “positive puzzle” never interrupted at all. Though they had no conscious knowledge that their puzzle was themed, their subconscious minds noticed the pattern and primed them for action.

It’s a little frightening when you think about it. We believe we’re exercising free will when we’re actually highly influenced by outside factors.

But in truth, the subconscious is an enormous gift. Without the ability to process everything around us subconsciously, each decision would take enormous effort. For instance, you might stand in the supermarket for two hours weighing the pros and cons between two perfectly good apples without unconscious decisionmaking.

Instead of pressuring ourselves and others to explain the unexplainable, it’s time to begin trusting the processes that occur behind the locked door.

Why We Fall for Tall, Dark, and Handsome Men

There is admittedly a dark side to thin-slicing. Sometimes, taking information at face-value — instead of digging a little deeper below the surface — can lead our judgments astray.

In the early 20th century, Warren Harding was quickly gaining acclaim in the political arena. He was tall, broad-shouldered, and handsome, and everyone who laid eyes on him believed in his abilities as a leader — he was the embodiment of dignity and power.

However, his political stances were vague at best, and his speeches never seemed to communicate much of anything. Still, Harding continued to climb the political ranks, from Ohio Senate, to lieutenant governor, to the US Senate. And all of this unfolded despite his average intelligence and an obvious lack of critical insight.

In 1920, when the Republican Party was gridlocked between two candidates, they turned to someone they could all agree on. Harding was elected as the 29th president of the United States, and to this day is commonly considered one of the worst presidents in US history.

The Republican Party — and the public at large — associated Harding’s outward demeanor with leadership ideals so intensely that they voted a completely unqualified man into power.

Similarly, John Bargh’s word puzzle experiment proved that we all have unconscious connotations with certain words, and these connotations are so strong, they can change our behavior.

True thin-slicing allows you to quickly process the important details in a situation, but strong associations often cut that process short. Instead of taking in the details, you stop at face value and assume to know the truth.

Allowing connotations based on surface-level information to dictate your behavior is the very core of bias and prejudice.

Often, people have many professed, conscious ideas. These are values we uphold and strive to live by. We act deliberately and purposefully in pursuit of these ideas. But we all also have unconscious ideas about a myriad of things. These are the automatic connotations that crop up and that we act on without thinking. Since they’re unconscious, many of us aren’t even aware of that anything’s happening.

Imagine a midlevel manager who consciously values equality, but unconsciously has negative associations with certain ethnicities. Now, imagine that same manager is conducting job interviews. Studies have shown that your unconscious beliefs affect your body language and overall actions, so the manager would most likely exhibit different behavior depending on the ethnicity of the interviewee.

Perhaps the manager would make less eye-contact or smile less when interviewing people of a certain ethnicity. The interviewee’s unconscious mind will notice this, so he might be less confident or hesitate to speak. The manager, in turn, will notice this and may decide not to move forward with the hiring process.

These types of situations make it clear why someone mediocre — like Warren Harding — may hold a very valuable position in government or at your company.

So how do we overcome unconscious bias and allow true thin-slicing to take place? Is it even possible to change a process we aren’t aware is happening?

Our unconscious impressions are not outside of our control. The connotations we hold are formed based on our personal experiences, which means those associations evolve and grow as we do.

Creating Structure for Spontaneity

Making the best decisions requires a healthy compromise between deliberate and instinctive thinking.

But great decisions also require frugality. In other words, you must learn to be a great editor.

In the 1970s, Dr. Lee Goldman sought to solve a common problem in the medical field: accurately diagnosing heart attacks. Goldman realized that many doctors were resorting to conjecture when patients presented with chest pains. They often weren’t sure if the pain was a heart attack and ended up admitting the patient just to be safe. This led to overcrowded hospitals and overworked nurses.

In an attempt to remove the guesswork, Goldman poured over hundreds of patient charts and created an algorithm. Goldman realized that doctors only needed to focus on four specific risk factors in order to make an informed decision.

Medical professionals were sceptical — surely you needed to consider many more factors before making a potentially life-altering medical decision. But Goldman was firm. Focus on the four, and you’ll have your answer.

When his algorithm was eventually tested in a real hospital, the results were undeniable: The algorithm was over 95% accurate for diagnosing heart attacks. Goldman removed all of the unnecessary information that was clouding the doctors’ decisions and focused on what really mattered. In short, the algorithm was an editor.

Many of the decisions we have to make rely on intuition rather than logic. When you overthink an intuitive problem, you are disrupting your natural ability to make accurate judgment calls. Sports are a prime example. Players have to make splitsecond decisions in high-stress environments. They aren’t doing complicated calculations about ball trajectory in their heads while playing. They’re relying on muscle memory.

More information isn’t always better. Excellent intuitive decision-making requires that we edit out all of the unnecessary information and focus on the key points.

When Craig Kallman, president of Atlantic Records, first heard rock musician Kenna’s demo CD, he was hooked. Kallman immediately knew that Kenna was special and wasted no time spreading the word about his talents. Music industry executives agreed. Knowing that most radio stations will only play music proven to have mass-market appeal, they quickly sent Kenna’s music to research firms.

This is where Kenna’s career halted before it even began. The research results were overwhelmingly negative. The general population didn’t share the executive’s enthusiasm.

The radio industry isn’t alone in its reliance on market research. Many industries love using things like focus groups to determine the potential success of a product. Companies feel it provides a level of certainty. Unfortunately, most focus groups rely on snap-judgments — rapid cognition — for their results, and these judgments simply aren’t certain by nature.

Coca-Cola discovered this in the 1980s. It conducted blind taste-tests with consumers and saw that people preferred Pepsi over Coke. Assuming that consumers knew what they wanted, Coke adjusted its recipe to be more like Pepsi’s.

To the company’s shock, the new product was a complete failure, and Coke soon had to bring back their classic recipe. More focus groups were conducted and consumers still preferred Pepsi in taste tests. Nevertheless, Coke continued to lead the market in sales — a fact that has never changed over the years.

What the researchers at Coke failed to realize was that thin-slicing requires context. Sure, in a blind sip you might prefer Pepsi, but you never actually pick soft drinks that way. When you pick a soft drink in the real world, there are dozens of other factors affecting your opinion, from the color of the packaging to the unconscious connotations you have with the brand image.

In a blind test, you rely only on your snap-decision of the taste, but in reality your choices are affected by so much more. Hence, focus groups don’t reliably predict consumer behavior.

Field experts are the only exception to this rule, because they have spent years researching, learning, and studying. Professional food tasters will be able to tell you exactly why they prefer a certain cookie over another, and they are unlikely to change their minds. Their experience allows them to peek behind the locked door.

An average person, however, may say they like a cookie in a focus group, but then they’ll choose the opposite in the grocery store. They don’t have access to what’s happening behind the locked door and therefore can’t explain their reasoning.

Unfortunately for Kenna, many industries, including radio, continue to take these snap-judgments in focus groups as solid indicators of what people will enjoy in the real world, even when deeper research proves this to be unsound reasoning.

The Delicate Art of Mind-Reading

On a chilly February night in the Bronx in 1999, Amadou Diallo was enjoying some fresh air outside of his apartment building. Four police officers, members of the NYPD Street Crime Unit, came to a halt in front of Diallo’s building.

Over the next seven seconds, a chain of events took place that would change countless lives.

An officer called out to Diallo, thinking he matched the description of a known criminal in the area. Diallo turned to run back inside, unsure who the men were since they were in plainclothes. The officers gave chase, their suspicions heightened by the man’s attempt to escape. Diallo reached the vestibule of his apartment and reached into his pocket.

The officers, assuming he had a gun, yelled for him to stop. But Diallo was a Guinean immigrant with shakey English, so he continued to dig. He then removed something black from his pocket. “Gun!” yelled two of the officers, before opening fire, causing one of them to trip backward down the steps. The remaining offers also opened fire, assuming their fellow officer had been shot.

They fired a total of 41 shots at Diallo, whose crumpled body now lay in the vestibule. One of the officers approached him to remove the gun. To his shock and dismay, Diallo clutched nothing but a wallet.

Mind-reading isn’t some science-fiction terminology: it’s our ability to understand someone’s thoughts and intentions based on their facial expressions. This is a classic example of thin-slicing and one that we do in every human interaction. When your friend cracks a joke, you quickly look at their face to determine if they are being silly or sarcastic. When your girlfriend says “I love you,” you peer into her eyes to judge her sincerity.

It is usually easy to tell the difference between love and indifference or sarcasm and silliness. And it should be easy to differentiate between someone who is scared and someone who is aggressive.

Diallo was 22 and small of stature. He was unarmed and terrified, having recently been mugged by a group of men in the neighborhood. How did the officers miss so many cues that undoubtedly flashed across Diallo’s face during the tragic encounter?

The sad truth is, we’ve all done it. Temporary mind-blindness has caused countless arguments and misunderstandings in our lives, though most don’t have devastating consequences like in Diallo’s case. Why do we often fail at mindreading?

There are two possible answers to this question.

According to Gavin de Becker, author of The Gift of Fear and head of a security firm in L.A., one common reason people lose the ability to mind-read is simply a lack of time. In De Becker’s industry they call it white space — the distance between an attacker and a potential victim. White space directly correlates to accurate mindreading; the more white space, the longer people have to read minds and react.

When we have no time to react, we become temporarily mind-blind.

This is why police departments are moving toward one-officer squad cars. When officers work alone, they are more likely to wait for backup instead of rushing into a situation. They have more time to consider every clue available to them, including facial expressions.

Another reason we become temporarily mind-blind is lack of training or practice in high-stress situations. We can develop stronger rapid cognition skills through experience. The officers who killed Diallo were all fairly inexperienced under the conditions they were in.

Despite what crime dramas would have you believe, most police officers go their entire careers without shooting at someone. Roughly only 10% of officers use their firearms. And those who do experience extreme levels of stress and trauma.

When we encounter life-or-death situations, or extremely high-stress scenarios, our bodies react in ways to protect us. Time seems to stand still. You may experience tunnel vision or temporary deafness, and some people even lose control of their bowels. This is the body’s evolutionary way of editing out extra information so you can focus on the biggest threat at hand. This also means we become totally oblivious to cues that allow us to mind-read.

According to former Army Lt. Col. Dave Grossman, our optimal performance during stress occurs when our heart rate is between 115 and 145 beats per minute. Higher than 145 and we will begin to experience a decrease in mental faculties. If our heart rates reach 175, we are essentially reduced to the same cognitive function as animals. In these situations, there is no chance of reading minds or noticing cues.

We can stop this dangerous increase in heart-rate and keep our mental faculties through experience and practice.

The Lessons of Blink

Rapid cognition is an incredibly powerful gift, but we are often negligent of the power we hold. After Amadou Diallo was killed, many people came to the defense of the officers, believing police duty requires snap-decisions and thus some mistakes are to be expected in high-stress situations.

Many people assume that because these moments of snap-judgment come from behind a locked door, we are incapable of controlling them. But this simply isn’t true. We must acknowledge that even the smallest influences affect our unconscious ideas, and we must take action to change those influences.

Only in the past several decades have women joined the ranks in orchestra music. Previously the industry was full of men because everyone believed that women were not biologically capable of excelling in orchestra. It was a common belief that women simply lacked the power to play on par with the men, particularly with brass instruments.

And then they started conducting blind auditions. Screens were placed in front of the musicians and judges had to rely on their ears alone. Suddenly, women were being hired to play in orchestras. Had women improved suddenly? Of course not. The judges had been allowing their unconscious ideas affect their decisions during auditions.

But they realized there was a problem, and they took action.

Being unaware of what lies behind your locked door is not an excuse for poor rapid cognition. You can always take action to change the subtle impressions that guide your unconscious mind.


At the end of the day, the rapid cognition that allows us to make fast decisions is simply our judgment. It is a powerful tool that can be easily influenced by many factors. We must carefully guide our influences and take action against bias.

But when do we rely on our instincts — our snap judgments — and when we do rely on logic?

Generally, if you are facing a straightforward problem, logic and reasoning are helpful. The more information, the better. But if your problem is a bit hazier and has many variables, you are most likely better off relying on your rapid cognition — especially if some of those variables are out of your control.

Perhaps this answer isn’t satisfying or clear-cut. The truth is, there isn’t a definite answer for every situation because the power of our unconscious mind is complicated. Perhaps it isn’t an all-or-nothing question.

Often, the best way to move forward to is to find a healthy combination of conscious logic and unconscious thin-slicing.

About the author

Malcolm Gladwell is an author, journalist, and public speaker. He has written for The Washington Post and The New Yorker and previously received the National Magazine Award for profiles. Gladwell has written several books, including New York Times bestsellers The Tipping Point and Outliers. In 2005, Gladwell was named among TIME magazine’s 100 most influential people.