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Wow, Did You See That? Nope, I Did Not.
July 20, 2014 2:19 PM   Subscribe

Person Swap (SLYT) This is one of those "awareness test" things but done more with more of the flare of a magician's trick. There are a lot of interesting details in how they pulled it off.

See also Colour Changing Card Trick.

Sort of Related 2004 MeFi post.
posted by Michele in California (24 comments total) 11 users marked this as a favorite

Yeah, but did you see the bear walk by throwing a ball?
posted by xingcat at 2:25 PM on July 20 [3 favorites]

Or the gorilla suit?
posted by roomthreeseventeen at 2:38 PM on July 20 [3 favorites]

The weird thing about visual processing as I understand it in a vague layman's sort of way (IANA neurologist or visual physiologist) is that your brain actually does not receive everything in our visual field or anything close to it; there is all kinds of neural mediation that occurs in the system of neurons behind the receptors, as well as in the optic nerve, which is itself responding to signals from the brain, all of which is optimized for the way you ordinarily use visual information; with presumptively uninteresting information discarded at every stage. So it's not just that you fail to notice something you don't expect, but that you in a very real sense don't see it at all.
posted by George_Spiggott at 2:47 PM on July 20

I feel like the fovea/peripheral split does not get enough attention in these sorts of things.
posted by Brainy at 3:17 PM on July 20

Or the gorilla suit?
posted by roomthreeseventeen at 6:38 AM on July 21

I simultaneously love and hate that the "behind the scenes" of the colo[u]r-changing card trick has a gorilla suit visible, yet it is never used in any way
posted by DoctorFedora at 3:24 PM on July 20 [2 favorites]

This would certainly work on me. Strangers frighten me, and on the occasions I'm forced to interact with them, I never look directly at them. If I'm ever a witness to a crime the only description I will be able to gve the police is "Probably human."
posted by Horace Rumpole at 3:33 PM on July 20 [8 favorites]

I wonder how much of this is just the social conditioning to NOT tell strangers "HOLY SHIT, I THOUGHT YOU WERE A DUDE!". Or in the milder examples, "whoa, you look different for some reason." (One guy does basically say this.) Most people will assume that they must have made some strange mistake and say nothing.
posted by jcreigh at 3:39 PM on July 20 [7 favorites]

You definitely see hesitation in those folks, though, even the ones that didn't explicitly call it out.

It feels to me like a bank. You have multiple ATMs, and in 98% of their transaction things are totally normal. Every person enters the correct PIN, you register accordingly, easy peasy.

1.65% of the time, you get customers who enter the wrong PIN. They're legitimate, but they just fat-fingered or forgot it. It's easily corrected by just taking a second sample of the same information ("An error has occurred, please try again.").

0.25% of the time, an extremely unusual but honest error has occured. A couple accidentally picked up the wrong ATM cards when they left the house and they both used their anniversary as their PIN, or a solar flare tripped just the right series of bits to permanently make Jerry Weisenheimer's card look like Sally Scooperton's card, so you'd better come inside and chat with us for a minute... oh, yep, this is just a glitch, sorry for the inconvenience.

.009% of the time, something illegitimate is going on and it's clearly suspicious: a customer withdraws an above-average amount of money at an unusual time of night. Your systems should probably save the ATM video on that one for a few extra days, just in case.

And now you get to the last .001% of the time, comprised of all the weirdest legitimate and illegitimate situations. Some of them can be easily recognized with human input, some are easily recognized by computer analysis, some are both... and a tiny, tiny fraction of that last 0.001% can't be conclusively resolved without serious investigation by someone with both human intuition and advanced programmatic tools.

Those people and those systems are fucking expensive, and they only protect us from one out of every hundred thousand incidents. That's already pretty rare, and even when they fail we have limits in place to prevent almost any individual incident from costing us more than $1,000, and we're federally backed so that the vanishingly rare exploitation of the remaining scenarios will enjoy heightened scrutiny by the Feds, who are so thorough that there's no chance that any of that last 0.001% would slip through the cracks.

So jeez, we've got all our bases covered, right?

Take a moment.

posted by Riki tiki at 3:42 PM on July 20 [1 favorite]

If I'm ever a witness to a crime the only description I will be able to gve the police is "Probably human."

I have heard that people who are crime victims and had a gun pulled on them often cannot describe their assailant but can describe the gun in great and glorious detail.

Also, my understanding is that when people meet someone in an unusual context, half the time, they do not recognize them. In other words, if you know Bob at work and run into him at the mall, you might not realize it is the same person. Context is a big part of how we recognize people and this is part of what they work with in the video to trick the people.

jcreigh, it looks to me like most of them really do not notice. The woman whose companion says something to her looks really shocked by the news. I think the guy who says "I thought it was another guy" is basically led to conclude he was wrong -- or that it would be socially unacceptable to push the issue -- by the kind of response he gets.
posted by Michele in California at 3:42 PM on July 20 [4 favorites]

For those who did take a moment, my point is this:

All the heuristics we have in place to distinguish "normal" from "wait a sec... okay, normal" from "abnormal"? They are themselves based on heuristics with exactly the same properties and limitations.

Perhaps human perception is a fractal of bad design. Maybe the things we rely upon the most are so sufficiently reliable, that we didn't develop ways to recognize when they've failed... let alone correct for those failures.
posted by Riki tiki at 3:50 PM on July 20 [1 favorite]

This is just loose bonding, in action.
posted by chavenet at 4:00 PM on July 20

Without wanting to ruin things too much, it's TV. They have edited out any reaction they didn't want you to see. You have no idea how many people called them out immediately and how few were fooled.
posted by Neale at 4:01 PM on July 20 [2 favorites]

my understanding is that when people meet someone in an unusual context, half the time, they do not recognize them.

I am terrible with this. I know a LOT of people (mostly just the 'Hi, how's it going level) in the various race series and support series/programmes that I race with. Because of the fairly small nature of racing and the fact that you to some extent all travel together (a 'Calendar' of 4-5 race series travel together, with additional 2-3 occasional series on a semi regular basis) there are the same 6-700 people all the time plus about 3-400 regular people there every other race or so. Because I subcontract, I participate in two main calendars so have two sets of these semi familiar 1100 people that I bump into or walk past at the various race events. Of these people I know maybe 2-300 to varying amounts.

Context is ESSENTIAL. Even when a person moves teams (and hence team uniforms) I can utterly fail to recognise them. Worse, they move series and race with a different programme so aren't even in context with the same cars. There are so many people that I recognise (from seeing constantly) but don't know that I struggle when someone I DO know changes context. They slip into the same 'recognise but ignore' band until either they say something or it clicks with me.

I am also terrible with names. I know hundreds of people called 'mate', it seems. Or at least, that answer to it.
posted by Brockles at 4:04 PM on July 20 [1 favorite]

I can't watch it on my phone so I'll have to wait til tomorrow at "work". But just to say that Derren Brown is amazing.
posted by billiebee at 4:35 PM on July 20

I agree with Neale, this is less than convincing and a little contrived. I'd want to see it unedited because I rather imagine many folks would have not been fooled. Plus lots of folks wouldn't want to have been bothered. I'd like to see numbers.
posted by charlesminus at 6:09 PM on July 20

The number according to this test is 75%
posted by RobotHero at 6:11 PM on July 20 [2 favorites]

I started watching this video knowing there was some kind of trick. I think I probably even read the title "Person Swap." I watched the first four interactions and then got bored, thinking that the trick was that people didn't notice that the face on the big canvas being carried through was the same face as the guy asking directions (is it? I'm bad at faces, particularly on video). It wasn't until I started reading the comments here that I realized what must have happened, went back to watch the video, and actually saw it.
posted by pocketfullofrye at 8:07 PM on July 20 [3 favorites]

There's also a movie I watched in my film studies class where one character is played by two different actresses and about half the class, including myself, didn't catch on. Though I remembered being confused a couple times thinking "who is this character?" and then figuring out from context who it was and then brushing it off, assuming it's just the costume or lighting or something accidentally made me not recognize her.
posted by RobotHero at 8:18 PM on July 20 [1 favorite]

We know that the brain takes all sorts of shortcuts, and throws together bits of information in ways that may be functional most of the time, but are actually kind of messy.

And yet I know more than one person who will swear that their brain was absolutely infallible when they FELT THE PRESENCE OF A GHOST.
posted by univac at 11:42 PM on July 20 [1 favorite]

I am determined to understand Riki tiki's point, but I don't think this coffee is strong enough to help me make the mental breakthrough right now. I shall try again later when I am properly awake.
posted by Decani at 11:58 PM on July 20

Link not available in UK, this one does though: Person Swapping
posted by Gordafarin at 1:25 AM on July 21 [1 favorite]

This trick would absolutely work on me. I am terrible at facial recognition until I've met someone several times, and in the interim I identify people by hair color/style. It took me about 3 weeks after starting a new job to be able to tell apart 2 blonde coworkers who, in retrospect, looked nothing alike at all.

Reminds of this Amy Schumer sketch.
posted by Librarypt at 7:16 AM on July 21

When I watched Schindler's List the first time, I thought Liam Neeson and Ralph Fiennes were the same person for most of the film. Scene after scene of Fiennes shooting people in the back from the rooftop of his concentration camp villa, and me thinking, dear god, how's he ever going to come back from this one? And that's at my most alert. Just imagine something like this!
posted by two or three cars parked under the stars at 9:39 AM on July 21 [2 favorites]

A lot of people have trouble recognizing faces. The inability to recognize faces at all is called face blindness or Prosopagnosia.

There used to be a website at which had a really excellent analogy using stones. It no longer exists but if you search for "prosopagnosia stones analogy" you can still find sites that refer to it (and link to the now link-farmed url). (example)

The stones analogy used pictures of stones to show what it is like to wrestle with this problem. It showed a group of stones together and made the point that the smallest, the largest, and the one of a different color were readily recognized as individuals. But the multiple stones that were similar in size, shape and color could not be readily told apart. Then it added, for example, hair to the stones to show how that can impact things. Face blind people can be really thrown if you change your hair dramatically, whether cutting it, dying it, or just putting it up when you normally wear it down.

Here is an older site I am somewhat familiar with on the topic:

Face blindness is a very socially impairing disorder. Failing to recognize people who think you should recognize them is often interpreted as extremely rude (or worse). But the reality is that for "normal" people, recognition is heavily context dependent. This is less obvious in some circumstances than in others. If you live in a small town and interact with the same people, you may know everyone there on sight. But if you live in the big city or otherwise have contact with substantially more people, it can become pretty challenging to keep track of everyone.

As people travel more and as our social circles generally become broader and less stable, we probably need to get better at accounting for and accommodating the fact that, no, we can't remember everyone or recognize everyone on sight. We probably need to do that for security reasons but also to reduce social friction.
posted by Michele in California at 9:52 AM on July 21

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