It was a viral video going around for a while — the Invisible Gorilla experiment. (If you never saw it, you can watch it here… the rest of this blog-post is a spoiler!) (Although to be fair, just saying the words “invisible gorilla” is a spoiler already… oh well.)
This experiment from 1999 was quite astonishing. Framed as a test, the video asks you to count the number of times some kids pass a basketball back and forth. Partway through, a person wearing a gorilla suit saunters into the video, mugs right in front of the camera, plain as day, and leaves. In the experiment, fully half the people who watched this video did not notice the gorilla. They were too busy counting basketball passes.
None of those people would believe they could miss a friggin’ gorilla. When the gorilla was pointed out to these people, some insisted that the experimenters had switched the tape! They pretty much universally said “of course I would see a gorilla.” But yet, half of them were wrong. The new book by one of the authors of this experiment is engaging and worth a read.
If you didn’t see the gorilla in that video, you aren’t stupid. Even after many experiments, the researchers couldn’t find any way to predict the people who would notice the gorilla (or whatever other random thing they added, in any context). Regardless of the experiment or the person, some people notice the external details sometimes, and sometimes they don’t. But people always think they will notice all major details. Worse, when they see somebody not noticing an important detail, they assume those other people are idiots… even though it’s just dumb luck that they noticed it themselves.
EDIT (bonus paragraph): the first thing commenters say is “well, but the gorilla blends in!” That was the first thing the psychologists assumed, too. I’ll give you that they are psychologists, but in this particular case that doesn’t mean they’re completely stupid. They tried numerous additional experiments, including, for instance, one where you are supposed to count the number of small black digits floating by in a big white empty screen. Then a gigantic red letter E flies by. Half the people still missed the giant letter. It doesn’t matter what the context is, and it’s not about something blending into the noise. Even incredibly distracting interruptions will still get tuned out. That’s why this is an interesting phenomenon.
We have a highly-ingrained belief that we notice everything around us, but the truth is that we have very selective attention. When we’re focused on something else, we often miss very obvious things in our surroundings. But we believe only idiots would do that.
This is the crux of the book, although it unfolds into a lot of other interesting experiments and diversions. The authors are concerned with how this affects our court system, among other things. I am more concerned with how it affects the games we make.
Instant Death
It’s an MMO designer classic: stick some giant horrific monster into an area to keep players on their toes. If the players refuse to run away from said monster, they get killed. But they always have plenty of warning. “The earth shakes when the giant walks,” says the designer — “they can’t help but notice that! So it’s not unfair. It’s just something to keep them on their toes.” Or how about the old “random firetraps in the middle of a raid dungeon” trick? Spices things up without being unfair, right?
Unfortunately, half the time these sorts of encounters end in unavoidable death. The players are deeply engaged in playing the game — watching the little bars tick down and using the right skills at the right time — and half the time, they miss your deathtrap cues, no matter how obvious you think they are. When they die, they are understandably upset.
The really frustrating part is that other players think they’re morons. Hell, the players themselves often come to think they’re morons. “How did I manage to get ganked by an elite cavalry unit when you can hear the horse steps a mile away?!” The general conclusion seems to be that the average MMO player is really stupid. Right?
But in actuality, designers are being just as misguided as the players. Most designers would agree that it isn’t fun to die instantly without any warning. But yet half the time, these “easily avoidable” deathtraps go unnoticed. There’s nothing the players could do to pay more attention. It’s not possible to focus on the gameplay and also notice 100% of the other stuff going on all the time.
The result is that half of those kills are insta-kills without any warning. They are the antithesis of fun. Worse, other players often make fun of them for something they couldn’t avoid. What a stupid thing to include in an MMO!
To HUD or Not To HUD
A related study referenced in the book looked at pilots being trained to use new HUD systems. The pilots would get so transfixed managing the HUD data that they would miss things going on out the window — things happening literally underneath the translucent HUD, or just an inch away from it. It’s not about visually missing something, it’s about our brain completely filtering things out as noise.
We’ve all played games where the GUI was more important than everything else going on. Hell, I still have no idea what the 3D characters do in Rock Band — I can never take my eyes off the fretboard GUI long enough to notice anything.
Among designers who have learned about this psychological phenomenon, there is a tendency to try to integrate the gameplay right into the world. (I have often been in this camp, with mixed success.) For instance, in Red Dead Redemption there is no health meter. The screen just gets redder and redder as you are about to die. I find that this does make it easier me to focus on the world around me instead of constantly glancing at that damned health bar… but on the other hand, I am often surprised when I suddenly keel over dead. (I can hear you thinking “But the screen turned bright red! How could you not notice that! Oh… wait, right.” Just because it’s impossible to miss doesn’t mean we won’t miss it anyway, half the damned time. HALF THE TIME!)
How Do We Fix It
The authors of The Invisible Gorilla want to make you aware of the fact that your attention is extremely selective — that you are missing crazy things happening around you all the time. That is a great thing to teach people, but that’s not the role of video games.
Most video games (including the ones I like to make) are escapism, much like books or TV. Here, we want you to feel good about yourself. We don’t want to teach you that your brain can miss important things going on around you — instead, we want to hide this flaw in the human brain. When you’re playing a video game, you shouldn’t be surprised about unfortunate outcomes. You shouldn’t go “How did I die?!” or “Where did that level-80 elite mob come from!?” Those questions indicate that the player is feeling abused. Moreover, they aren’t learning anything, either (except, perhaps, not to play your game): it is not possible to “learn to pay more attention”.
The only band-aid fix is not to have nasty traps like that in your game. That isn’t really a deep “fix”, though, because the problem happens with rewards, too – I mean, you are probably running past tons of ore mines, rare monsters, spontaneous treasure chests, and who knows what else, without ever noticing them. On the one hand, that stuff didn’t kill you, so it doesn’t hurt you. On the other hand, designers didn’t factor in that you would miss half the stuff they stuck in, so the game may feel more sparse and empty than they expect… because if you’re focusing on combat, you are literally missing half of the cool stuff around you.
More Research
Until reading this book, I didn’t realize that psychologists have done quite so much research on selective attention. The book is obviously not too concerned with video game design, but I’m hopeful that there are experiments by human-computer interaction psychologists that may help us understand how to work with this issue when designing games. If I find some, I’ll post about them. (And if you have leads, please share them!)



