Monday, November 5, 2012

My Invisible Gorilla Moment

There's a famous Psychology experiment where people are shown a short video of two groups of students passing basketballs around.  They are told to count the number of passes that one particular group makes.  After they're done, the researchers ask the subject how many passes they counted.

They ask a few more questions about what they observed, and then they ask, "Did you see the gorilla?"

Half the people answer, "No, what gorilla?"

When they show the video again, the people see that halfway through the video, a person dressed in a gorilla suit walks right into the group and waves.  The gorilla is in the video for nine seconds, in plain site.  When they see it a second time, many of the subjects don't believe they're watching the same video they just saw.  How could they have missed the gorilla? It was right in the middle of the video!

This experiment teaches us a lot about human observation.  The problem with the gorilla is not that people aren't looking at it (subsequent tests that track eye movement prove this), but that they just don't SEE it.  Numerous studies have shown that it's an eerily common occurrence for humans to be looking right at something and yet not be able to see it.  Unexpected sights just don't register in our brains.  This principle can be applied to countless environments, from the witnesses in a courtroom to drivers to pilots landing a plane to doctors looking at x-rays.

There doesn't seem to be any pattern to who notices the "invisible gorilla" and who doesn't.  It's not people who are smarter, or more focused, or better at multitasking, or are left-handed or who have a penis.  In general, it's always about 50% of the people who see it and 50% of the people who don't.  The only predictor is expectations.  If you tell people to look for something unusual, they're more likely to spot the gorilla. But in everyday life, when something unexpected happens, our brains have a harder time registering it.  None of us is immune to it.  It's how the human brain was built.  It's all about expectations.

After I read about this phenomenon, I remembered a significant "invisible gorilla" moment from my own life.

In my family, on our birthdays each of us kids got $25 worth of presents.  It was always thus, so I never expected anything more than that. So one year, on my 11th or 12th birthday, I was really surprised when after I'd opened all my presents, my dad told me to go out to the back deck.  I could tell from the tone of his voice that there was something special out there.  From the dining room, where we had just had my fancy birthday meal, I looked out the window to see what it might be, but the view was obstructed.  To get outside I had to go through the kitchen and family room.  I was so intent on getting out to the deck to see what great thing was waiting for me that I sprinted through the house.  I busted through the back door onto the deck, but nothing was there.

I went back into the house to see what the deal was.  My family had all run after me from the dinner table, and they were standing in the family room.  My mom laughed, "He ran right past it!"

I looked in the hallway and there was a brand-spanking-new Schwinn Stingray 3-speed bicycle.

My Invisible Gorilla.  I don't remember it looking quite this dorky, but then again, I'm learning how crappy human memory really is.
I was so intent on getting outside to discover what my special birthday surprise was, I ran right past this sweet beauty, and didn't even SEE it.  Who expects to see a new bicycle in the living room?  Not me.

The invisible gorilla phenomenon is yet more evidence that we completely underestimate how limited our brains really are.  It has implications for memory as well.  It's shocking how unreliable our memories really are.  Study after study shows how we construct memories in our head that can be quite different from what actually happened.  Most people think they know why & how they think things.  They don't.  This is why we need science-- to prove how wrong our intuitions can be.  To read more about how stupid you (and I) are, go to the Invisible Gorilla website.


Dan S said...

I would bet that those who do the worst job of counting passes have a high percentage of seeing the gorilla. After all, it's the distraction of counting passes that prevents you from "seeing" the gorilla.

Tim said...

You would think that. After all, if you just asked people to watch people passing basketballs around without counting anything, you would expect everyone to see the gorilla. But according to subsequent tests, they "found that who noticed and who missed an unexpected object was unrelated to several basic measures of attention capacity... if an object is truly unexpected, people are unlikely to notice it no matter how good (or bad) they are at focusing attention."

They've done other tests in other contexts (see the videos on their website). The only determining factor seems to be expectations-- whether you expect something unusual or not.