# 75

A man comes to the rabbi and complains about his life: "I have almost no money, my wife is a shrew, and we live in a small apartment with seven unruly kids. It's messy, it's noisy, it's smelly, and I don't want to live."
The rabbi says, "Buy a goat."
"What? I just told you there's hardly room for nine people, and it's messy as it is!"
"Look, you came for advice, so I'm giving you advice. Buy a goat and come back in a month."
In a month the man comes back and he is even more depressed: "It's gotten worse! The filthy goat breaks everything, and it stinks and makes more noise than my wife and seven kids! What should I do?"
The rabbi says, "Sell the goat."
A few days later the man returns to the rabbi, beaming with happiness: "Life is wonderful! We enjoy every minute of it now that there's no goat - only the nine of us. The kids are well-behaved, the wife is agreeable - and we even have some money!"

Biases are “cognitive illusions” that work on the same principle as optical illusions, and a knowledge of the latter can be profitably applied to the former. Take, for example, these two cubes (source: Lotto Lab, via Boing Boing):

The “blue” tiles on the top face of the left cube are the same color as the “yellow” tiles on the top face of the right cube; if you're skeptical you can prove it with the eyedropper tool in Photoshop (in which both shades come out a rather ugly gray).

The illusion works because visual perception is relative. Outdoor light on a sunny day can be ten thousand times greater than a fluorescently lit indoor room. As one psychology book put it: for a student reading this book outside, the black print will be objectively lighter than the white space will be for a student reading the book inside. Nevertheless, both students will perceive the white space as subjectively white and the black space as subjectively black, because the visual system returns to consciousness information about relative rather than absolute lightness. In the two cubes, the visual system takes the yellow or blue tint as a given and outputs to consciousness the colors of each pixel compared to that background.

So this optical illusion occurs when the brain judges quantities relative to their surroundings rather than based on some objective standard. What's the corresponding cognitive illusion?

In Predictably Irrational (relatively recommended, even though the latter chapters sort of fail to live up to the ones mentioned here) Dan Ariely asks his students to evaluate (appropriately) three subscription plans to the Economist:

Ariely asked his subjects which plan they'd buy if they needed an Economist subscription. 84% wanted the combo plan, 16% wanted the web only plan, and no one wanted the print only plan. After all, the print plan cost exactly the same as the print + web plan, but the print + web plan was obviously better. Which raises the question: why even include a print-only plan? Isn't it something of a waste of space?

Actually, including the print-only plan turns out to be a very good business move for the Economist. Ariely removed the print-only plan from the choices. Now the options looked like this.

There shouldn't be any difference. After all, he'd only removed the plan no one chose, the plan no sane person would choose.

This time, 68% of students chose the web only plan and 32% the combo plan. That's a 52% shift in preferences between the exact same options.

The rational way to make the decision is to compare the value of a print subscription to the Economist (as measured by the opportunity cost of that money) to the difference in cost between the web and combo subscriptions. But this would return the same answer in both of the above cases, so the students weren't doing it that way.

What it looks like the students were doing was perceiving relative value in the same way the eye perceives relative color. The ugly gray of the cube appeared blue when it was next to something yellow, and yellow when it was next to something blue. In the same way, the \$125 cost of the combo subscription looks like good value next to a worse deal, and bad value next to a better deal.

When the \$125 combo subscription was placed next to a \$125 plan with fewer features (print only instead of print plus web) it looked like a very good deal – the equivalent of placing an ugly gray square next to something yellow to make it look blue. Take away the yellow, or the artificially bad deal, and it doesn't look nearly as attractive.

This is getting deep into Dark Arts territory, and according to Predictably Irrational, the opportunity to use these powers for evil has not gone unexploited. Retailers will deliberately include in their selection a super deluxe luxury model much fancier and more expensive than they expect anyone to ever want. The theory is that consumers are balancing a natural hedonism that tells them to get the best model possible against a commitment to financial prudence. So most consumers, however much they like television, will have enough good sense to avoid buying a \$2000 TV. But if the retailer carries a \$4000 super-TV, the \$2000 TV suddenly doesn't look quite so bad.

The obvious next question is “How do I use this knowledge to trick hot girls or guys into going out with me?” Dan Ariely decided to run some experiments on his undergraduate class. He took photographs of sixty students, then asked other students to rate their attractiveness. Next, he grouped the photos into pairs of equally attractive students. And next, he went to Photoshop and made a slightly less attractive version of each student: a blemish here, an asymmetry there.

Finally, he went around campus, finding students and showing them three photographs and asking which person the student would like to go on a date with. Two of the photographs were from one pair of photos ranked equally attractive. The third was a version of one of the two, altered to make it less attractive. So, for example, he might have two people, Alice and Brenda, who had been ranked equally attractive, plus a Photoshopped ugly version of Brenda.

The students overwhelmingly (75%) chose the person with the ugly double (Brenda in the example above), even though the two non-Photoshopped faces were equally attractive. Ariely then went so far as to recommend in his book that for best effect, you should go to bars and clubs with a wingman who is similar to you but less attractive. Going with a random ugly person would accomplish nothing, but going with someone similar to but less attractive than you would put you into a reference class and then bump you up to the top of the reference class, just like in the previous face experiment.

Ariely puts these studies in a separate chapter from his studies on anchoring and adjustment (which are also very good) but it all seems like the same process to me: being more interested in the difference between two values than in the absolute magnitude of them. All that makes anchoring and adjustment so interesting is that the two values have nothing in common with one another.

This process also has applications to happiness set points, status seeking, morality, dieting, larger-scale purchasing behavior, and akrasia which deserve a separate post

New Comment
[-]Jack410

Maybe you should write a post that describes the same effect but without the pictures, citations or good grammar.

Maybe u shld write a post that describes the same effect but wihout the pics, citaations or grammar.

I agree, all that good grammar just gets in the way. There's too little appreciation for bad grammar here on lesswrong.

Holy crap we're broken. Good info.

This is getting deep into Dark Arts territory, and according to Predictably Irrational, the opportunity to use these powers for evil has not gone unexploited.

I'm a little worried that calling (a/i)rrational persuasive techniques "Dark Arts", even in seemingly indefensible (though, it must be said, minor) cases like this, biases us against them and will make people averse to using them even when doing so is ethical and beneficial. What do others think? Am I overreacting?

Dan Ariely, who apparently learned his teaching methodology from Professor Quirrell

FWIW, I suspect most casual readers don't know about Methods of Rationality and were confused by this.

FWIW, I suspect most casual readers don't know about Methods of Rationality and were confused by this.

Well, they should fix that.

The label "Dark Arts" is itself an example of Dark Arts: romanticizing something to hide assumptions in it.

[-][anonymous]40

Nick Tarleton:

I'm a little worried that calling (a/i)rrational persuasive techniques "Dark Arts", even in seemingly indefensible (though, it must be said, minor) cases like this, biases us against them and will make people averse to using them even when doing so is ethical and beneficial. What do others think? Am I overreacting?

Here is a provocative thought. In my opinion, scientists nowadays command the trust and confidence of the general public largely thanks to the "dark arts."

Nobody except the scientists themselves and a tiny number of hobbyist enthusiasts who have invested the large effort to study the relevant material has the necessary competence to judge whether the work in any particular field is true and sound or just bullshit. (To be precise, in some applied areas, people can be reasonably confident because they constantly see useful new technologies coming out of the research efforts, but that's not the case for most fields.) Now, when scientists make outreach to the general public and try to popularize science -- thus reinforcing their status and authority -- it's absolutely impossible for them to argue things in a way that would be both: (1) correct and logically rigorous, and (2) comprehensible even to exceptionally intelligent and informed readers and listeners, let alone average ones.

Because of this, we get popular science materials that are, from an intellectually rigorous point of view, basically a pile of bullshit arguments for conclusions that are likely true, but for altogether different reasons -- reasons which the intended audience is utterly incapable of comprehending. Even the conclusions themselves are often so complicated and remote from everyday experience that they get presented in a way that is perhaps technically true, but virtually guaranteed to cause misunderstanding and puzzlement in most of the audience. Sure, some fields allow for decent popular presentations, like e.g. people studying the migration patterns of animals. But the stuff found in most pop-science treatments of, say, physics or evolution is just awful, and the silly and naive beliefs that masses of people form by reading them are even worse.

Therefore, for many areas of science, the bulk of the general public has no reason to believe that scientists are right except raw appeals to authority and the "dark arts" pop-science bullshit they've been served. Yet, our political system involves a significant democratic component, and scientists must maintain their intellectual authority in front of wide masses of people lest they lose government and philanthropic support. This might well be impossible to do without serving them a steady diet of "dark arts" pop-science that, on its own merits, has barely any more logical validity than all sorts of superstition and charlatanism that scientists are competing with for authority and public prominence.

Here is a provocative thought. In my opinion, scientists nowadays command the trust and confidence of the general public largely thanks to the "dark arts."

Yes, you're right, it is probably too off topic. I replied to the above comment without too much thinking about the context. I'll delete it and cache the thought for a more appropriate moment.

That seems a bit extreme. Why not put it on the open thread now, even if you plan on elaborating later?

Don't worry, I can quickly reproduce the same argument whenever a more opportune context comes up.

I like the reference to "Dark Arts", but I've removed the Quirrell part on your suggestion.

How to See Color and Paint It is about a practical situation where you really would rather not be subject to color illusions.

It starts out with an illusion like the one in this article-- the author takes his art students to the shore of a bay at dusk and asks them the color of the brick buildings across the water. The students say "red", and then he has them look at the buildings through holes in 3" x 5" cards--- the buildings are blue!

Not only are colors as perceived strongly influenced by expectation and surrounding colors, a lot about them operates below conscious perception. It's claimed that white is actually a hue which is too light to be easily identified, black a hue which is too dark, and gray and brown are respectively cool and warm hues which are too muted to be easily identified.

The book teaches artists to look at color patches on objects individually, and mix paint separately for each patch rather than mixing what seems to be the major color of an object, and then modifying it for highlights and shadows.

I haven't worked with paints following the book, but just reading it produces a short-lived altered state of consciousness for me. It's amazing to realize that a t-shirt when being worn in ordinary light shows only very small areas of the color I think it is-- most of it is either much lighter or darker.

Now I'm wondering if having read that book a few times is part of why clumsy photoshopping drives me up the wall. The way the light and shadows don't hang together is completely obvious to me, and it must not show up for most people.

Crashing Through, a book about a man who recovered his sight late in life and had to work very hard to make any sense of it, mentions that if you can't see optical illusions (these were perspective-based, not color-based), you can't see.

Any theories about why people like optical illusions?

Sorry no cite, but I've read about a study which found that women in bars tend to prefer the dominant man in a group. This led me to deduce two possibilities: a group of men which trade off dominance on different nights (this would take a lot of trust, I think), or more likely, men who keep going to bars with the same dominant friends, hoping that the magic will rub off on them, and not realizing that their own subordination is the magic.

This led me to deduce two possibilities: a group of men which trade off dominance on different nights (this would take a lot of trust, I think)

This is pretty much a standard part of being a 'wingman' in PUA.

Dan Ariely, who apparently learned his teaching methodology from Professor Quirrell

Epic reversed causality much?

Heuristics and biases researchers -> Eliezer Yudkowsky -> Professor Quirrell.

This is really too long for a comment, but I couldn't resist:

Tom Marvolo Riddle, who had lately taken to calling himself Lord Voldemort, shut his eyes. When he opened them again, the envelope was lying on his bed, just as he had hoped. He studied the papers inside with barely concealed glee. Over several pages was a very long string of incomprehensible letters and numbers. Almost shaking, he typed it into the computer, where it said "ENTER RANDOM SEED", and pressed enter. The screen filled with - could it be? - pages of comprehensible text. He had to restrain himself from giving a very un-Dark-Lordly whoop of triumph.

This was outstandingly clever even for him. The Time-Turner, the computer generating random text blocks that - with the right seed - would be coherent hypotheses, the dungeon of prisoners to serve as subjects in hastily conducted impromptu experiments. And the only stable time loop being the one where he ended up with the secrets of human behavior.

He hit PRINT, then called in Dolohov, the trustworthy one. "Take these psychology hypotheses and test them on the prisoners downstairs. If you get p < .05, no, make it .01, and if you can think of ways they'd be useful in manipulating people, take these pages of letters and numbers, copy them, stick the copy in this envelope, and put it on my desk. Otherwise, increase the ASCII value of the last character in the random seed by one, and put that on my desk. No questions, just do it. And do it in the next twenty-four hours."

That would take care of the Time-Turner. He was glad his model lacked the length limitations of the standard version: six hours wouldn't have been enough time for Dolohov to finish the tests. Those idiots at the Ministry had no idea how easy it was to extend the gas mileage of one of those things. Or maybe they did and were too squeamish to go around obtaining the secret ingredient. He smiled lovingly at the jar of kitten hearts on his desk. Those things were like the duct tape of evil magic - you could use them for anything.

Now it only remained to make sure no one else ever copied his trick. The Ministry he'd already dealt with - Merlin bless that fool Minister Bagnold and her "it's inconceivable anyone could break through our wards" policy. He'd apparated into the Ministry, put a curse on their whole stockpile of Time-Turners, and gotten out with no one the wiser. The artifacts would still function for little things like attending extra classes, but try to use them for anything...clever...and they'd do their best to scare the user into submission. Cryptic warnings not to mess with time, that kind of thing.

But his own Death Eaters were more of a problem. They'd notice if their master suddenly and inexplicably learned all the secrets of the human mind. Some of the brighter ones might start asking where he'd learned them. Some of the really bright ones might try figuring out exactly what those secrets were and how to use them themselves. He needed a distraction. Something that would turn their minds away from the Dark Lord's late nights in his study tinkering with Time Turners and computers, something that would make the secrets of the mind not even worth obtaining.

Suddenly he broke out into a grin. Make something a secret, and of course people would look for it. Make it mundane, better yet make it low status, and people wouldn't give it a second thought - that was the lesson of Muggle science. Was that on the paper he'd given Dolohov? It must be. He'd tell everyone he learned the secrets from the Muggles. Everyone knew they came up with a bright idea every so often, but the ancient and noble bloodlines who populated the Death Eaters would sooner die than go rooting around in Muggle books like Mudbloods trying to find them.

He'd fake an identity as a Muggle scientist - maybe even two, now that he'd mastered duplication with the Time-Turner, and get the secrets published in a Muggle journal. If anyone asked, he'd been reading Muggle journals, and there was nothing unusual about his possessing the secrets of the human mind at all.

His Quirrell alias was already a professor, but he was saving that for a rainy day. And Voldemort and Tom Riddle were right out. That meant someone new. He took out his sketchpad. He did so love anagrams. That TOM MARVOLO RIDDLE == I AM LORD VOLDEMORT one still sent chills up his spine. He'd want something at least that good if he was going to be a Muggle researcher or two. After a few abortive attempts, he finally found something he liked.

DOR DANIEL KM & DOR AMOS TVERSKY, IL == YIKES, I'M DARK LORD VOLDEMORT-SAN

Right, then. Dr. Daniel Kahneman and Dr. Amos Tversky, Israel. And while he was in the area, he could pick up the Spear of Destiny. Kill two birds with one stone.

He'd just need a few supplies, and he'd be ready to go. He picked up his miniature scapel and put in a call to the local animal shelter, whistling merrily to himself.

And here I thought lesswrong would be the one place on teh internets where I wouldn't get confused by obscure Harry Potter references and consequently feel out of place for not reading it.

This is marvellous. I wouldn't have even seen this comment if I hadn't seen a Lw link to an xkcd forum thread that linked here.

[-][anonymous]00

I was going to mention time turners, but it looks like I'm 17 days too late.

And yet Ariely's first paper was published in 1994, which implies that a fictional Ariely from HP could have learned from Quirrell.

[-][anonymous]00

I was going to mention Time Turners, but it looks like I'm 17 days too late. Course, I always felt Time Turners were a cheap way out for a writer anyways.

I suggested below that there is more going on in the cube illusion than merely the brain making local comparisons of colors relative to their background. I wanted to test this claim out by generating an image that had the same arrangement of colors but without some of the additional cues present in the 3D renderings.

I generated the image below based on a higher res version of the original illusion (at bottom for comparison). The RGB values are the same as in the bottom image. There is still quite a powerful effect but it seems to me that it is indeed less powerful than in the original (specifically the yellow effect on the right is muted for me), suggesting that the visual system is doing something more complex than local color comparisons. I've been staring at these images for too long now to be sure of my judgments any more however. What do others think?

I think the tops of the cubes in the 3D picture look brighter because of the "shadow". Your visual system is imagining a light source coming from the upper right. There's no such effect in the 2D picture.

Yes, I think this is part of what is happening. I also think my perception of less apparent 'yellowness' in the grey tiles in the non-3D version is due to there being fewer cues to lead the visual system to conclude that there is a blue light illuminating the scene.

This reminds me of two separate Stoic mental practices -- though I should point out that I do neither of them habitually and they have no scientific studies measuring efficacy or life improvement or anything :-)

The first, negative visualization, is aimed at bringing more satisfaction to one's life. Quoting from Stoic Psychological Tactics Part One:

Negative visualization is the single most powerful tool in the stoic toolbox. In the simplest form it’s spending time visualizing loosing the things you value most. In modern times think along the lines of loosing your job, having your car stolen or the death of a loved one.... To a stoic, not only is the glass half full, he also has a glass (it could get stolen or broken) and to top things of it’s a glass and not even a ceramic pot. It doesn’t give a peculiar taste to the liquid inside and you can even enjoy the color of the liquid! What a wondrous thing this glass is that we take for granted.

The second tactic I'm reminded of is the stoic version of meditation. Quoting from Stoic Psychological Tactics Part Five:

Seneca advises us to periodically meditate on the events in our daily lives, how we responded to them and how we -in accordance with Stoic principles- should have responded in stead. It’s very simple actually, before you go to sleep lay there for a moment (or kneel beside your bed if you prefer) and think about how your day was. This type of meditation is completely unlike the meditation of a Zen Buddhist. Where a Zen Buddhist sits still for extended periods of time trying to think of just one thing, calming his mind and focusing on his breath or a koan a Stoic will be all over the place with his mind. Focusing on all the events of the day and reliving them. Total chaos if you ask a Zen Buddhist, functional if you ask a Stoic.

The thing that worries me about these techniques is that they seem to be aimed at making a person satisfied with their environment but very focused on changing their mental and behavioral patterns. This runs counter to my general understanding that people's environments are generally easier to change and have much larger impacts on behavior than are generally recognized. It also makes me worry that it might be part of a memetic "person retention strategy" which could be the basis of people becoming life long stoics even if it wasn't truly nourishing.

In any case, the thing I was trying to illustrate was that we can use imaginary comparisons to guide our expectations and emotions, people have known the general trick for many centuries, and it seems like a generally useful principle for designing similar practices which could actually be tested for efficacy :-)

The thing that worries me about these techniques is that they seem to be aimed at making a person satisfied with their environment but very focused on changing their mental and behavioral patterns. This runs counter to my general understanding that people's environments are generally easier to change and have much larger impacts on behavior than are generally recognized.

But it's one's mental and behavioral patterns that generally keep one from actually changing their environment. Many of our patterns are also homeostatic in nature: if the environment takes away one way to get the need met, we find another one. Such patterns are much more difficult to fix environmentally.

Paradoxically, being "satisfied" (i.e. neutral) to one's environment is more conducive to changing it. Stated more precisely, perceiving one's environment as non-threatening is vastly more conducive to changing it, than perceiving it as a threat. Our brains don't work nearly as well (or as creatively) when the environment is perceived to be threatening, relative to one's own resources.

(Btw, Buddhist meditations do include visualizing the loss of valuable things, such as one's own life. Also, the Zen Buddhist's mind is also going to be all over the place during meditation... the objective of the meditation is to see through these thoughts as false hopes and false fears distracting one from the objective neutrality of existence.)

[-][anonymous]20

The first, negative visualization, is aimed at bringing more satisfaction to one's life.

I know this sounds silly, but the first time I heard of this life-changing technique was in Star Wars episode III, in this quote by Yoda:

"Train yourself to let go of everything you fear to lose."

Quote with context

I think it's similar to systematic desensitization which is what I personally believe is the main function of hypnosis (although I'm uneducated about the subject). My application of this concept consists of relaxing while thinking about bad scenarios, over and over again for a few days or weeks.

I used paint to take part of one cube, split through the "special" square and move it over to the other image - my brain told me that I was seeing one colour, but the second the opposite image came in contact with its rival square my brain began telling me the square had been grey all along. Remove it and the effect was reversed. It was almost as if my mind was trying to erase any false memories - quite a fun experience.

The “blue” tiles on the top face of the left cube are NOT the same color as the “yellow” tiles on the top face of the right cube. Each tile in both sets is made of pixels of several different colors. The "blue" tiles on the left are made of several shades of slightly bluish-gray; the "yellow" tiles on the right are similarly composed of several shades of slightly yellowish-gray.

Such illusions may indeed be real, but that image does not seem to be a good example.

Edit: Interesting. The higher-resolution version of the image (in mattnewport's post) is indeed as described, i.e. the colors of the relevant tiles are identical. Is the deviation in the lower-res image a result of compression?

It looks like it's compression. The image in the post is JPEG, which uses lossy compression; the one in mattnewport's post is PNG, which uses lossless compression.

I think it might be some dodgy processing or gamma correction at some point in the image's history. Some of the 'yellow' tile pixels in my image have very slightly different RGB values than the 'blue' tile pixels. Applying a gamma curve, saturation adjustment or other image processing could have resulted in the greater differences seen in the image in the post.

I know it was just for introduction, but that was an awesome illusion, much better than the more widely-known one mentioned in this previous LW article. I mean, wow, when you draw a line from the "blue" to "yellow" tiles the same color as both tiles, the line looks like it's changing color, even though it can't be! Amazing.

Of course, the point I made about the previous optical illusion still stands: yes, your visual cognition is "wrong" for this rare occasion, but the same heuristic that makes you wrong here allows you to be right in more common cases, like if you saw this kind of thing in real life.

Unfortunately, the corresponding phenomenon doesn't happen for the related "comparison bias" you discuss, so a similar point can't be made there.

I mean, wow, when you draw a line from the "blue" to "yellow" tiles the same color as both tiles, the line looks like it's changing color, even though it can't be!

Cool idea, here's what it looks like.

Thanks for providing that image. This is a very powerful effect.

For instance, I have to focus on it very hard to temporarily not see it.

Can anyone NOT see this effect easily? Or is it fully universal?

I can see the colors changing in the modified image, however, the effect seems to be a lot more subtle for me than for other people.

I was very confused by the first image, because the tiles others are identifying as yellow on the right cube look gray to me; that is, I don't see any yellow boxes on the right cube; I had to look at the modified image just to know what boxes to compare. I've never been diagnosed as colorblind, but have on rare occasions argued with people about the color of items that have a similar gray appearance. Anyone care to hazard a guess what's going on here?

[-]Kevin120

Is it possible that you are super-un-colorblind? http://en.wikipedia.org/wiki/Tetrachromacy

If you turn out to be humanity's third identified tetrochromat, I want 500 karma.

Color vision deficiency? Variant cone cell pigmentation in your X-chromosome(s)? I imagine running some color vision tests might be informative.

Interesting. I can "focus on" the four gray (blue) tiles on the left cube and see them as gray, but I can't see the yellow tiles on the right as anything but yellow just by thinking.

Hands down the most startling optical illusion I can remember seeing.

Any color blind people look at this? I blocked off the surrounding color with a pair of envelopes, and the line then looks the same color, but it seems to be darker on the left side (yellow-tinted cube) than on the rest of the line. Edited for clearness.

Neat - when I look at it up close, I see the 'line's color changing' effect Silas mentioned. But when I back off, I instead see a grey line connecting the squares, including a ghost image of the line overwriting part of the colored square.

Yeah, I don't think this illusion (which I posted in the colour constancy discussion you mention) is an appropriate example to use as an introduction to the Predictably Irrational story. Your brain is not being 'fooled' here - it is doing exactly what it is supposed to do, which is solving the inverse rendering problem and not identifying RGB values. The anchoring effect with the prices of subscriptions is not really the same kind of thing at all.

Ariely then went so far as to recommend in his book that for best effect, you should go to bars and clubs with a wingman who is similar to you but less attractive.

It's commonly observed that many girls use this exact tactic when going to bars and clubs.

And some people have advised hitting on the less attractive one on the theory that she'll be more likely to be receptive to advances.

Or to make the other one jealous.

Your brain is not being 'fooled' here - it is doing exactly what it is supposed to do, which is solving the inverse rendering problem and not identifying RGB values. The anchoring effect with the prices of subscriptions is not really the same kind of thing at all.

Why not? Presumably the brain is 'supposed' to perceive differences more easily than absolute values as well, because that's what was useful on the sorts of problems that shaped the brainware we now use to compare prices.

Your visual system is not evolved to be a colorimeter because that is not actually very useful for the kinds of things we use our visual system for. Thinking that your brain 'should' identify the same RGB values as the same 'colors' in a different context reflects a confusion about what invariant properties of the world the visual system represents as 'color'.

Our conscious experience of color is related to the spectral composition of light that reaches our retinas but the RGB value of a pixel is not sufficient to describe the more complex qualia we label 'colors'. If there is any 'failure' captured by this illusion it is a failure to understand what a good job the brain does of extracting useful information from the complex pattern of light that falls onto our retinas rather than a failure of the visual system. A colorimeter is a relatively simple \$90 device. Matching the human visual system's performance on the inverse rendering problem is an unsolved hard AI problem.

The anchoring phenomenon which can result in poor choices in certain circumstances on the other hand does reflect a 'failure' in the sense that a generally useful heuristic may lead us to make poor judgements. I'd say it is an example of misapplying a heuristic to a problem it is ill suited for. I think comparing it to the colour constancy phenomenon is misleading and inapt.

I totally agree that those functions of the visual system are features and not bugs, but I still think the analogy to biases holds; after all, there's a strong argument that that biases can be features too. It's all a question of whether they're being used in the sorts of situations for which they were designed, or whether they're in an unusual situation where they break down. In the case of vision, that's specially designed optical illusions, but practically all modern thought is outside the original design specs for our cognitive heuristics.

Thinking that your brain 'should' identify the same RGB values as the same 'colors' in a different context reflects a confusion about what invariant properties of the world the visual system represents as 'color'. ... If there is any 'failure' captured by this illusion it is a failure to understand what a good job the brain does of extracting useful information from the complex pattern of light that falls onto our retinas rather than a failure of the visual system.

Beautiful. Well said.

[-]ata60

I agree with mattnewport's use of "supposed to" if it's in the sense of current usefulness. "It is doing exactly what it is supposed to do" as in "it is doing what we'd generally want it to do". The ability to screen off tinting and lighting variations is probably more useful than the ability to perceive absolute colours. (If you see a Rubik's cube through a yellow-tinted window and you want to figure out what colours are showing, then you don't want the window to affect your answer.) But if we're looking at a list of subscription options or choosing between TVs at a store, it would be vastly more preferable to have some neutral, non-relative way of evaluating the options, some way of having a \$2000 TV evoke the same amount of happy desirability feelings whether you see it next to a \$4000 TV or a \$200 TV.

I'm not sure that the same neural mechanism is used to compare colours and to compare prices, but I could be convinced. (Is there any research on it? Are there any conditions that impair one of these processes, such that we could study them and see if the other process is impaired too?) If they are indeed the same, and I could choose to knock out that part of my brain or not (with no other side effects), then I think (very tentatively) that I would. I think I could deal with perceiving the blue tile as grey if it made me a much more rational economic decision-maker.

[-]Jack70

I really doubt that same neural mechanism is involved. Like P= 0.0005. We're dealing with totally different areas of the brain that evolved hundreds of millions of years apart. I'm not even sure I see an obvious sense in which the optical illusion corresponds to the cognitive bias.

I don't think it's mechanically the same, or that there's a value-of-magazine-subscriptions equivalent to double opponent cells in the visual cortex, but I think the two processes are conceptually solutions to the same problem.

The general problem is trying to pick out salient features from what's currently in the attention without being distracted by the macro-level problem of how what's currently in the attention differs from everything else.

So in color vision, that's something like determining what parts of a field are redder or greener than others without being distracted by the entire field being redder than usual because it's sunset. In purchasing, it's something like deciding which of two meals is better value than another without being distracted by the whole menu being more expensive than normal because it's a fancy restaurant.

[-]ata00

Yeah, that was my intuition (though I hadn't thought about it enough to get that confident). I was just posing the question to see if anyone actually wanted to argue a connection between the two processes or if they were only using it as an analogy. I got the impression that Yvain was using it as an analogy but that Nick was arguing or assuming that both cases were actually using the same cognitive processes.

Seems I'm late to the party, but if anyone is still looking at this, here's another color contrast illusion that made the rounds on the internet some time back.

For anyone who hasn't seen it before, knowing that it's a color contrast illusion, can you guess what's going on?

Major hint, in rot-13: Gurer ner bayl guerr pbybef va gur vzntr.

Full answer: Gur "oyhr" naq "terra" nernf ner gur fnzr funqr bs plna. Lrf, frevbhfyl.

The image was created by Professor Akiyoshi Kitaoka, an incredibly prolific source of crazy visual perception illusions.

You're missing citations or links for the experiments you mentioned. While most of us could figure out that Predictably Irrational is a book by Ariely and the experiment is somewhere within, you should really specify that.

I unfortunately don't have the book with me, so I can't give you page numbers. I gave a link to the Amazon page for the book, but I realize that's not optimal. There's a link to an online Scribd version of the book I can give you if you want it, but it's of questionable legality and I figured having that in the main article wasn't the sort of thing we wanted LW associated with.

If you tilt your head sideways and look at the top faces simultaneously from below the plane of the top face you'll see that they are the same color (a very dark grey).

[-][anonymous]00

it all seems like the same process to me: being more interested in the difference between two values than in the absolute magnitude of them

You can go even more general than that - this really illustrates the entire, flawed process of the way that we think. Judgment and decision making seems to take the form of "use my subconscious pattern-recognition machinery to determine what sort of situation I'm in, then make a judgment of that situation based on just a few context cues." Manipulate the cues I rely on for judgment (such as relative magnitude), and you can manipulate the decisions I make.