logo 12min

Start growing!

Boost your life and career with the best book summaries.

Start growing!

Boost your life and career with the best book summaries.

logo 12min

The Invisible Gorilla Summary

10 min read ⌚ 

The Invisible Gorilla PDF Summary

How Our Intuitions Deceive Us

Follow your gut, they say.

Christopher Chabris and Daniel Simons beg to differ.

In The Invisible Gorilla, they claim that it’s sometimes much better to not judge the book by its cover.

Who Should Read “The Invisible Gorilla”? And Why?

If you are interested in the inner workings of your mind and all the tricks it plays on you on a daily basis, then The Invisible Gorilla is just the book for you.

If it helps, it’s somewhat similar to books such as You Are Not So Smart and Predictably Irrational; and it questions some of Malcolm Gladwell’s findings.

But more on that later.

About Christopher Chabris and Daniel Simons

Christopher Chabris
Daniel Simons

Christopher Chabris is an American research psychologist.

After receiving his B.A. in computer science at Harvard, he worked as an AI program manager in the University’s Psychology Department for the next five years. He received his Ph.D. in 1999.

A chess master since 1986, Chabris is currently Associate Professor of Psychology and co-director of the Neuroscience Program at Union College in Schenectady, New York, Senior Investigator at Geisinger Health System, and a Visiting Fellow at the Institute for Advanced Study in Toulouse, France.

Daniel Simons is an American experimental psychologist, a Professor in the Department of Psychology and the Beckman Institute at the University of Illinois.

He has a B.A. in Psychology from Carleton College and a Ph.D. from Cornell University.

Mostly, his work focuses on subjects such as inattentional and change blindness.

Somewhat unfairly, Simons and Chabris won the Ig Nobel Prize in 2004 for their “Invisible Gorilla” experiment, “one of the most famous psychological demos ever.”

“The Invisible Gorilla PDF Summary”

In Blink, Malcolm Gladwell attempted to remind people of “the power of thinking without thinking” and to demonstrate, in no uncertain terms, that intuition is oftentimes better than extensive analysis, due to the fact that it is preprogrammed to tune out extraneous information and focus only on the relevant data.

If you remember, one of Gladwell’s famous examples included a purported ancient Greek statue known as kouros; even though careful scientific analysis incorrectly judged it to be genuine, art experts were able to guess it was fake in the blink of an eye.

However, in the Invisible Gorilla, Christopher Chabris and Daniel Simons argue that Gladwell fails to see the big picture, and that, in reality, there are just as many situations which prove that the opposite is at least as accurate.

As an example, they cite the case of bibliophile Thomas James Wise, whose literary forgeries were exposed only after two young experts, John Carter and Graham Pollard, meticulously analyzed the forged books and published their results in a 400-page book titled An Enquiry into the Nature of Certain XIX Century Pamphlets.

The moral of the story?

The story of Thomas J. Wise is just one example of deliberate, scientific analysis overcoming flawed, intuitive judgments; but just as Gladwell’s kouros story does not prove that intuition trumps analysis, our Wise story does not prove that analysis always trumps intuition. Intuition has its uses, but we don’t think it should be exalted above analysis without good evidence that it is truly superior.

And, as expected, that’s what The Invisible Gorilla tries to prove.

It is a book about “six everyday illusions that profoundly influence our lives: the illusions of attention, memory, confidence, knowledge, cause, and potential.”

Let’s have a look at them all!

Key Lessons from “The Invisible Gorilla”

1.      The Illusion of Attention: “I Think I Would Have Seen That”
2.      The Illusion of Memory: “I Remember Perfectly”
3.      The Illusion of Confidence: “I’m Better Than the Score Shows”
4.      The Illusion of Knowledge: “I Know More Than I Do”
5.      The Illusion of Cause: “I’m Not Superstitious… Just a Little Stitious”
6.      The Illusion of Potential: “I Could Have Been Someone….”

The Illusion of Attention: “I Think I Would Have Seen That”

In 1995, Boston police officer Kenny Conley was chasing a shooting suspect when an African-American undercover officer was mistakenly taken down and beaten up by other policemen in his nearest vicinity.

Conley was tried and later convicted of obstruction of justice and perjury because the jury didn’t buy his story that he hadn’t noticed the beating up of his colleague.

And, let’s face it: Conley’ story was not exactly a believable one. Now, how could he miss the battering of a black policeman happening right next to the fence he was climbing to try to catch the criminal?

Well, hold your horses and spare a minute to watch the clip below before continuing below:

Did you see the gorilla?

Chances are – you didn’t because more than 1 in 2 guys doesn’t.


Because we’re not programmed to!

When we focus on one thing – like the counting of the number of times the players in white pass the ball between them above – our mind isn’t interested in anything other than that and ignores even giant slow-moving gorillas in the middle of the screen!

That’s probably what happened in the case of officer Conley: too focused on catching the criminal, he may have missed the beating up happening near him.

The illusion of attention is all about anticipations and expectations; since we’re not prophets (and there will always be a black swan lurking from around some corner), this is a very dangerous illusion.

Case in point: half of all motorcycle accidents involve collisions with cars, and two-thirds of them are the direct result of a car turning left and not noticing the motorcycle.


Because the driver is expecting – and is wary of – another car exclusively.

The Illusion of Memory: “I Remember Perfectly”

There are some people who have an excellent memory, but it’s nothing more than a simple brain rule that your memory is continually lying to you.

“Our memory has no guarantees at all,” writes Freud in The Interpretation of Dreams, “and yet we bow more often than is objectively justified to the compulsion to believe what it says.”

Freud pinpoints the catch perfectly: our brain has evolved to simultaneously remodel our memories and make us believe in their accuracy.

That’s merely a fact of life and the reason why 63 percent of all people believe that memories are basically film recordings.

However, they are not!

An experiment suggested by the authors of The Invisible Gorilla shows how they work in actual fact. You can try it yourself.

First, spend a few seconds looking at this list of words: bed, rest, awake, tired, dream, wake, snooze, blanket, doze, slumber, snore, nap, peace, yawn, drowsy.

Now cover your screen and try to remember as many of the words as you can; spend as much time as you like.

If you are like 40 percent of the people, you’ve probably included the word sleep in your list.

But, look again: that word is not in the list.

True, all of the words above are related to it, but your brain has fabricated the memory of it being present, because, by nature, it doesn’t it doesn’t record events, but reconstructs them.

There’s a big difference between the two!

And that difference boils down to this: even if you remember something vividly, there’s no way you could know if your memory is correct or not unless there’s some video/photographic evidence.

The Illusion of Confidence: “I’m Better Than the Score Shows”

Here’s an interesting statistic: more than two-thirds of Americans and Canadians think they are more intelligent than your average Joe.

The problem?

Your average Joe should be smarter than half of the population – neither more or less.

In other words, about 20 percent of the people living in North America are confident that they know more than they actually know.

But, you’ll justly object, how would we know if they are right or not? After all, intelligence is not an exact science!

And since Chabris and Simons are the first ones to agree with your claim, they have already conducted an experiment in a community where the numbers are much more precise and where they tell more than a simple story.

Namely, the chess community.

Strangely enough, Chabris and Simons uncovered much the same pervasion of this illusion of confidence: 75% of the chess players at the World Open in Philadelphia and the U.S. Amateur Team Championship in New Jersey thought that they were underrated.

And not by little: by an average of 99 points!

In chess, it’s pretty difficult to regularly beat an opponent rated 100 points above you; and yet, most of the people, despite numerous losses to precisely this kind of opponents, think that they can.

Ironically, if everyone who thinks should be rated higher is rated higher, the only thing that would change is the standard.

And there’s another twist to this story!

Namely, in The Descent of Man, Charles Darwin observed that “ignorance more frequently begets confidence than does knowledge.”

Justin Kruger and David Dunning proved this in an aptly titled 1999 study, “Unskilled and Unaware of It.”

The gist of it is a paradox: the less skilled you are, the less knowledge you have of your unskillfulness. Hence – the unwarranted confidence.

The Illusion of Knowledge: “I Know More Than I Do”

It doesn’t matter whether you’re an expert in your field or not; in many cases, your guesses for the future may be just as good as the most uneducated person alive.


Simply put, because we don’t know the future and, no matter how much things we know about the present, there’s always the chance (nay, the inevitability) of a black swan.

Consider the following examples:

• In 1957, Herbert Simon and Allen Newell, winners of the A.M. Turing Award in 1975 (Simon also won a Nobel Prize in Economics in 1978), predicted that a computer would be able to beat human chess players within a decade; they were very, very wrong;

• In 1968, David Levy, a computer programmer and an avid chess player, bet four other computer scientists the very opposite: that no computer will ever be able to beat a human chess player; in 1989, Levy lost to Deep Thought and in 1997, Kasparov lost to IBM’s Deep Blue;

• Even better – not included in Chabris and Simons’ book – Irving Fisher, USA’s greatest economist at the time, predicted that the “stock prices have reached what looks like a permanently high plateau” back in 1929; three days before the market crashed.

Socrates believed that he knew nothing – and it was because of this that he was dubbed the smartest man of his day and age by the gods.

It seems that there’s a lot of truth somewhere in there; many people know a lot less than they claim that they do; and this is what Nassim Nicholas Taleb constantly raves against.

It’s very, very, very dangerous to do that.

The Illusion of Cause: “I’m Not Superstitious… Just a Little Stitious”

Like it or hate it, “our minds are built to detect meaning in patterns, to infer causal relationships from coincidences, and to believe that earlier events cause later ones.”

On the face of it, there’s nothing wrong with either of them – they all help us lead more meaningful lives, sometimes even guiding our most important decisions.

For example, a doctor guesses your disease based on a pattern of symptoms, and a sports coach establishes his tactics after carefully deducing the patterns noticed in the behavior of the other team.

However, dig a little deeper, and you’ll see the problem: it is because of these patterns that we sometimes don’t see how random the world actually is.

In other words, there’s no man on the moon – these are just some randomly scattered moon lakes; also, you can’t really hear “Satan” when you play “Stairway to Heaven” backward unless you ready yourself to hear precisely that.

And therein lies the rub: if we can only see the patterns we’ve previously acquired, then we’re pretty susceptible to brainwashing, not to mention inherently limited to a worldview created by our prejudices and superstitions.

Of course, the place you’re sitting at bears no relation to the score of the game; your brain just tricks you into seeing a pattern and creating a relation between two simultaneous events.

The truth is: you’ll have to try pretty hard to beat it.

The Illusion of Potential: “I Could Have Been Someone….”

“I could have been someone,” sings the male voice in The Pogues’ brilliant Fairytale of New York. “Well, so could anyone,” answers the female singer.

This discussion sums up the last illusion analyzed by The Invisible Gorilla, the illusion of potential.

The illusion of potential, write Chabris and Simons, “leads us to think that vast reservoirs of untapped mental ability exist in our brains, just waiting to be accessed—if only we knew how.”

And it combines two beliefs.

First and foremost, that “beneath the surface, the human mind and brain harbor the potential to perform at much higher levels, in a wide range of situations and contexts, than they typically do;” and secondly, that “this potential can be released with simple techniques that are easily and rapidly implemented.”

You know what we’re talking about: no matter how many scientific studies claim otherwise – and regardless of the fact that it is utterly illogical – you still think that you use only 10% of your brain.

And, thanks to many bad to average movies and false studies, that there are some things which can easily and promptly awaken the rest of your brain.

For example, do you know that if you listen to Mozart, you become instantly smart?


But do you also know that this – and other claims such as these – have been transformed into multimillion-dollar businesses even though there’s almost no scientific support for them?

Like this summary? We’d like to invite you to download our free 12 min app for more amazing summaries and audiobooks.

“The Invisible Gorilla Quotes”

Incompetence causes overconfidence. Click To Tweet People are confident that they can drive and talk on the phone simultaneously precisely because they almost never encounter evidence that they cannot. Click To Tweet Your moment-to-moment expectations, more than the visual distinctiveness of the object, determine what you see—and what you miss. Click To Tweet The illusion of memory: the disconnect between how we think memory works and how it actually works Click To Tweet Whenever people think they know more than they do, they are under the influence of… the illusion of knowledge. Click To Tweet

Our Critical Review

There’s a lot to like in The Invisible Gorilla and barely anything to be critical about. “Thought-provoking, entertaining, educational and sobering, this book is a must read for those honest enough to realize they don’t or can’t, know it all.” (El Paso Times)

Describing it as “engaging and humane,” Paul Bloom, in a review for The New York Times, goes a step further and says that “The Invisible Gorilla just might teach us to be more humble, understanding and forgiving.”

Hopefully, it will.

logo 12min

Improve Your Reading Habits in 28 days

Explore key insights and ideas from 2500+ titles in audio and text

logo 12min

Improve Your Reading Habits in 28 days

Explore key insights and ideas from 2500+ titles in audio and text

Scroll to Top