The Invisible Gorilla - Book Summary

The Invisible Gorilla (2010) deciphers that intuition is not the guiding light as we always think. In fact, it is often wrong to rely on illusions. By debunking a few examples of common sense, Chabris and Simons demonstrated why our intuition is often unreliable.

This book is for anyone interested in psychology in general and in the workings of the mind in particular. If you're a manager, you'll also find new ways to make decisions through this exciting book.

About the author

Christopher Chabris  is a professor of psychology and executive director of a program in neuroscience at Union University in Schenectady, New York. He was also an accomplished chess player and often wrote about the game in the  Wall Street Journal.

Specializing in experimental psychology,  Daniel Simons is a professor in both the psychology department and the Beckman Institute for the Advancement of Science and Technology at the University of Illinois.

Chabris and Simons jointly won the Nobel Prize (awarded for “Make People Laugh, Then Think”) for their work on the invisible gorilla.

How can intuition deceive you?

“The confidence people display often reflects their character rather than knowledge, memory or ability.”

Do you see yourself as an intelligent, caring, and reasonable person? No matter how you describe yourself, you can often overestimate the brain's capabilities.

Many self-help books tell us to “follow our intuition” to make the right decisions in life. In this book you will learn why this is bad advice. In fact, it's easy to argue that you can't trust your intuition at all – you can't even trust it to spot a gorilla walking across the room.

Our intuition is often not to be trusted, even if we are taught otherwise.

Have you ever tried to navigate through a situation by listening to your intuition but ended up in an even more confusing mess? If so, you're not alone. Sometimes our intuition can be wrong. Here is the reason:

We are often taught to let our intuition tell us because "it's natural". These sayings are often based on the idea that our intuition – our ability to instinctively understand something – is an ideal tool for making decisions and making judgments about situations and events.

In recent years, self-help books on management and psychology have often emphasized decisions based on intuition over decisions based on analysis. In Malcolm Gladwell's book -  The Power of Thinking Without Thinking , the author emphasizes intuition over analysis. He tried to show this by telling the story of a Greek monument that appeared on an art market and was later declared a fake by experts who trusted their intuition. In contrast, some analyzes failed to show it to be a fake.

But our intuition has limits and can be really unreliable. There are many examples of fakes that have gone undetected by experts' intuition.

For example, a book dealer named Thomas J.Wise found and resold many manuscripts of anonymous books with famous authors' names. Libraries and book collectors were both convinced they were genuine, but after two British merchants analyzed and reviewed information about the author's life, the books were found to be fakes. .

Remember that we also have idioms about the limitation of intuition. For example, many people say "don't judge a book by its cover" because we know we can't judge anything by first glance.

We really don't see and pay attention as much as we think we do.

If someone was beaten on the street, you would recognize it right away, right?

Although we tend to notice the unusual, when we are carefully focusing on something else, we can miss the unusual.

The two authors devised the invisible Gorilla experiment and it became a classic example of how we can miss the obvious. In the experiment, participants were asked to watch a video of basketball players and count the number of goals scored by one of the teams. But in the middle of the video something strange happens: a man in a gorilla suit walks into the yard, stays there for about nine seconds, and pats his chest. Surely the participants must have seen that odd event. But the truth is no. About half of the people in that experiment didn't recognize the gorilla because they were so focused on counting the goals.

What's more, it's not uncommon for a Boston cop named Kenny Conley not to notice a black officer being beaten near a fence as he climbs up to arrest a criminal. Most of his attention was focused on the pursuit.

But we don't just miss out on things because we focus on something else - we don't realize what we're not looking for.

Imagine you are in a supermarket looking for things on your shopping list. While you do this, you are probably not paying attention to a lot of other things on the stalls. Of course this is no big deal, but what if we can overlook something big and dangerous? Yes. The truth is that we can even easily miss a motorcycle.

More than half of all motorcycle crashes involve cars, and 65% are the result of a car turning left and the driver not seeing the motorcycle. This happens because they are looking at other cars than motorbikes.

Our memory is not as clear and efficient as we think.

Too many of us confidently recall a vivid childhood memory only to be told by a family member that it wasn't really what happened. So why do we think we can remember things so accurately?

In a study by the same authors, 47% of people believe that memories do not change, and 69% say that memories are like videos that capture reality accurately, over time, and can be controlled. check again if you want.

But that's not true, because our memory often contains more information than what actually exists in the outside world. In one experiment, students read 15 related words such as "sleep" (slumber), "drowsy" and "tired". Ten minutes later, they were asked to repeat the words. Interestingly, the participants all mentioned the word "sleep" even though it wasn't on the list. Why?

Because all the words were related to the word “sleep”, the participants simply inserted another word from the same meaning group without realizing it. Instead of remembering the exact order of things or events, our memory is busier with remembering their meaning.

What's more, some memories don't come from where we think they are. Ken, a friend of the author, often tells an interesting story about sitting next to actor Patrick Stewart at a restaurant. He also remembers how the actor ordered an Alaskan cake and signed several people's names. He certainly didn't make up this story. But actually this has never happened to him but to either of the two authors. Ken didn't mean to lie – the story was told to him in so much detail that he thought it was his story!
This phenomenon is known as “memory failure” and is another way memory tricks us.

Confidence can deceive us

“Incompetence often causes overconfidence.”

You may think you are smart, perhaps even smarter than the average person. This is exactly how confidence can turn into an illusion.

It is true that we often tend to overestimate our own abilities, giving us confidence even for no reason at all.

In fact, surveys have shown that 69% of Americans and 70% of Canadians believe they are smarter than the average person. This is a bit odd as more than 50% is already average or below average. So about 20% are too proud of themselves.

The two authors also found similar results when interviewing chess players at a national competition. Chess players have different ranks but most still think they are underrated by 100 points. Why? Because the lower the skill, the more people appreciate their ability.

It turns out that the lower ranked chess players overestimate their technique.

But it's not just our overconfidence that can distort the truth – we also misinterpret other people's confidence as a believable expression of their abilities.

In a 1986 University of Rochester study, participants watched a video of a medical appointment. The doctor prescribes antibiotics in both clips, but in the first clip the man acts very confident and in the second the other man has to look up his illness to make sure he's right before prescribing. Most of the participants trusted the first doctor more than the second.

This indicates that when we see someone acting confidently, we tend to assume that they are better than those who are unsure of themselves.

We don't know as much as we think

Do you know how the toilet works? Chances are you're not. Often simple everyday things are beyond our common understanding.

The bicycle is an example. Most of us say we know how it works, but is that true? Psychologist Rebecca Lawson conducted an experiment where participants had to rate their knowledge of bicycles, then they had to draw one themselves.

This task seems more suitable for elementary school students, but many people fail miserably. On a scale of one to seven, the participants rated their knowledge on a 4.5, although some of them drew a chain connecting the two wheels and thus could not drive, or connect, - Knit with a chain, so it can't be steered. Most of us know what an object does but don't know why it does it. The more familiar something is to us, the more confident we are that we understand it.

We also mistakenly believe that we understand complex things if we receive a lot of information about them.

For example, in a study by behavioral economist Richard Thaler, participants invested money in mutual funds A and B.

The experiment lasted 25 years, and participants received information about activities for two quarters every month, every year, and every five years. Between breaks they have the option to change their investment.

Obviously the more updated the better, right? Is not! Those who are updated every five years end up making more than twice as much revenue

because they take a long-term view of their investment. In contrast, those who receive monthly updates change their investments more often and end up missing out on long-term revenue opportunities.

Obviously the more information the better, right? Is not! Those who stay informed every five years end up with more than double the revenue because they take a long-term view of their investment. In contrast, those who receive monthly updates change their investments more often and end up missing out on long-term revenue opportunities.

This indicates that having more information does not mean better understanding, it can even blur the big picture.

We have illusions about relationships and causes that don't really exist.

“Your minute-by-minute expectations determine what you see and what you miss more than the vivid difference of objects.”

We often hear the expression "there is no smoke without fire", but is it really true? No, we often believe that to be the case because narratives and consequences are deeply ingrained in human society.

A common example of this is that many people think that listening to songs with obvious sexual orientation will lead young people to engage in risky sexual behaviors. There are no scientific studies to prove this.

We also tend to see correlations when they don't exist.

People see patterns as a way to make sense of the world, but these patterns often don't exist. For example, to test whether people believe there is a link between weather and joint pain, Dr Donald Redelmeier and psychologist Amos Tversky asked patients with arthritis to record pain levels. everyday. After comparing the pain levels with the weather they saw that day, they realized there was no connection between the two.

So they decided to conduct a second experiment, this time with undergraduates. Participants were asked if they noticed any random matches between pain levels and weather information. Interestingly, 87% of them actually found a connection. Why? Because they focused on data that supported their previous perception that joint pain and weather were related.

So in what other areas do we find misleading connections?

When two things happen at the same time, we often believe that one leads to the other. Consider the following classic riddle: High drowning rates often coincide with a jump in ice cream sales. Do the two things affect each other? No, but hot summers are the reason for both: drowning is a higher-risk phenomenon as many people enjoy swimming, and ice cream is often a fun way to cool off in the water. hot summer.

We believe in the illusion of hidden possibilities that can easily be discovered.

If you weren't glued to Facebook all day, could you become a successful or intelligent artist like Albert Einstein? Probably not.

The truth is, we like to think that the brain has more potential than it actually is. We are willing to hold fast to the belief that we only use 10% of our brain capacity. But is this really true?

There's no way to measure the potential of the brain, and if we really only used 10% of our brains, the unused cells would atrophy and die, which means 90% of their brains. I'm dead! Even if this were true, what would it be like to have a large but almost completely hollow skull? Childbirth is dangerous for women because the heads are so big. If these heads have 90% unused gray matter, the risk of having children makes no evolutionary sense. And even so, in a survey conducted by two authors, 72% still think that 90% of their brains are unused!

Not only are we convinced of our untapped potential, we also think it's easy to unlock it.

An example of this is the Mozart effect, a theory put forward by the physicist Gordon Shaw, which asserts that listening to Mozart makes us smarter because its structure is quite similar to that of the brain. human set. Shaw conducted an experiment where participants listened to Mozart for 10 minutes, others listened to more pleasant music, and some just sat quietly. They then had to take cognitive tests to see how music affected their IQ. Those who listened to Mozart had an IQ increase of eight to nine points. Since that experiment, however, a few researchers have tried to repeat the test, but no one has found any evidence of the Mozart effect.

More than 40% of those in the two authors' study still believe that listening to Mozart unleashes their intelligence's potential.


Our intuition and the cognitive functions we rely on are not always reliable. In reality, we are not really as attentive and intelligent as we think we are and are not as connected in the world as we think.

Lesson learned:

Be careful what you look for.

When you're focusing your attention on something specific, you might miss out on other things. It can be something beautiful or exciting, but it can also be incredibly expensive, especially when you're driving on the road. So you should pay more attention to the things around you and anticipate the unexpected things that may happen.

Even in business, focusing on one thing means you can lose a lot of great opportunities right in front of you.