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How casinos distract

My father lived in Las Vegas for most of my teenaged years. While I never lived there with him, my step-grandparents (who raised me during that time) loved going there. Unsurprisingly, this meant that I spent a fair amount of time in Vegas growing up.

My grandparents, they were "old school" Vegas tourists. My step-grandfather was quite a gambler and played in a weekly poker game with his friends until his Parkinson's kept him from doing so. We used to stay in the Sands Hotel, made famous because the original Ocean's Eleven was filmed there.

The place was cool. At least, so I gathered. By the time I was staying there with my grandparents in the 90s it was old and somewhat dreary. But I was a kid and I loved plugging quarters into the claw crane games. One night I played on the same machine for so long that a waitress brought over a trash bag for me to put all my "winnings" (i.e., tiny stuffed animals) into. When I ran out of money, people were giving me a few bucks to let me keep going.

I cleaned out the entire machine. No shit. Probably the pinnacle of my life for about 25 years there.

Sadly, the Sands was famously demolished in June 1996 to make way for the Venetian:

So the Sands got old, but Vegas is still cool. Or, at least, it draws a hell of a lot of tourists... Clark County gaming and hotels did $19.5 billion in revenue in 2011.

How does this happen? Everyone knows that the odds are in the House's favor.

Well first, casinos rely on basic statistics to earn them piles and piles of cash. Even if the house has just a 1-2% advantage, the law of large numbers always prevails. The casinos don't need to do anything other than keep an eye out for cheats and they can just sit back and watch the money pour in.

But why stop there? We humans are easily manipulated, we are distractible, and we are limited by our brains.

Sure, the House has a statistical edge, but they also have a psychological edge. We're playing on their turf, in their stadium. They've got a major home-field advantage and you can bet your ass (haha) they take advantage of it.

Of course there's one obvious weapon in the arsenal used to break your will: alcohol. But even if you're a teetotaler your decision-making skills are certainly being manipulated. It's these more subtle manipulations that I'm going to talk about.

This post is conjecture by its nature: I've never worked for or with a casino so I don't know what they're actually doing. However, as a neuroscientist who studies the physiology of human attention and memory, I'm going to write about what I'd do if I were running a casino. (Caveat lector, read Kevin T. Keith's comment below: this is how I would do things, but does not necessarily reflect the reality in every casino.)

And remember, as a hypothetical casino-maker I don't care if you specifically aren't susceptible to any one of these given effects. Hell, I don't even care if the manipulation has the opposite effect on you than is intended. All I care about is the law of large numbers and the knowledge that, for a whole mass of people, there will be a shift in behavior on average that is in my favor.

First, you ever notice how round everything is on the casino floor? The tables are round, the chairs are round, the chips are round, the lighting designs are round, the patterns on the floor are round, and so on.

Basic psychological research shows that people consider rounded shapes to imbued with more positive emotional qualities (see this Dave Munger post for a primer on relatively recent research).

The goal here is to soften you up to actually get you to sit down and play. The House has an advantage, but it can't make use of it unless you actually throw down some money in the first place.

We've shown how casinos soften people up using visual cues such as shape. But of course, shape isn't the only thing we see. Look at the colors in the aforementioned Venetian:

(Edit: greenlight pointed out in the comments that the original image in the post was from the Venetian in Macau. The updated image is actually from the Vegas Venetian, but they have a similar color scheme. And this new image is way more amazing looking.)

Green card tables with white and gold everything else.

Let me introduce you to Plutchik's Wheel of Emotions:
Notice how green and gold are right next to one another in that loving, optimistic, submissive, ecstatic upper-left quadrant? Those are the exact emotions I want my marks customers to be feeling when they open their wallets.

Again, this doesn't have to be true, just good enough on average.

If I were running a hotel, I'd try an experiment: give every guest $20 in chips that can only be used on one specific game. Make sure the game is really simple to play, and give the House only the barest minimum of an advantage--say 0.1%. But make the game boring so no one really wants to play it. Make it so the game gives lots of little pay-outs.

We want to take advantage of the hot-hand fallacy to get people thinking they're on a roll, but we don't want the game to be any fun--we don't want people who don't have the free chips to actually play it.

We just want people to start playing.

So we've got our players hooked and wanting to play. Using visual cues we've got them optimistically excited, receptive, and in a generally good mood. Now what?

We need to befuddle them. Remember, the House advantages that you see for games like craps (~1%), roulette (2-5%), or blackjack (0.5%) are for optimal play. Our goal as the House is to induce sub-optimal thinking and behavior. Optimal play costs us money.

The trick? Distraction.

There's a well-known study by Shiv and Fedorikhin showing that if you tax people's working memory by making them remember a 7-digit string of numbers, people are more likely to make a less-optimal decision (they chose to eat chocolate cake versus the more healthy fruit salad option).

What most people don't report is that this effect only held true if the participants had to make a quick, snap-decision. If they had time to think about it then they were more likely to choose the healthy option despite the memory load. We need to keep people distracted.

The Shiv experiment is an example of cross-domain cognitive resource interaction. To unpack that: cognition is usually broken up into different domains, including emotion, decision-making, attention, working memory, cognitive control, and so on.

Now mind you, these are just poorly-defined semantic categories--placeholders for some underlying neural phenomena.

But the idea is that we have a limited amount of "cognitive resources" and that if I tax one--such as my working memory by having me remember 7 arbitrary digits--then my cognitive control and decision-making faculties will be impaired because my overall "pool" of resources is lowered due to the memory task.

According to brainSCANr, distraction is closely related to memory, attention, emotional regulation, and cognitive control. So in theory, we can manipulate any of those things to aid in distraction.

In my new post-doc lab, we study (among other things) the effects of distraction on cognition. One of my colleagues, Peter Wais, has shown that using a natural auditory distractor--ambient cafe noise as opposed to white noise--disrupted visual memory. In another study out of my lab, Wes Clapp (co-founder of NeuroScouting) found that the effects of distractors or interference on working memory occurs very quickly, within 100ms.

What this all means is that, in order to make the House more money, people need to make worse bets. To get them to make worse bets, we need them to make worse decisions and exert less cognitive control.

While we can manipulate decision-making and cognitive control directly through alcohol we can also use other tricks. The most reliable, simple way would be to tax memory or attention.

Why do you think there are so many bright lights and loud noises in casinos?

Why do you think slot machines make so much sound when they pay out? These noises are relevant distractors. They capture your attention, they charge up your emotions, and they get you to think that you too can win big! They get you to play more fast and loose.

Well, not me, of course.

I most certainly have never drunkly blown $40 on three-card Monte during Mardi Gras in New Orleans. I'm far too smart for that.

Pavlova M, Sokolov A, & Sokolov A (2005). Perceived dynamics of static images enables emotional attribution. Perception, 34 (9), 1107-16 PMID: 16247880
Shiv, B., & Fedorikhin, A. (2002). Spontaneous versus Controlled Influences of Stimulus-Based Affect on Choice Behavior Organizational Behavior and Human Decision Processes, 87 (2), 342-370 DOI: 10.1006/obhd.2001.2977
Wais PE, & Gazzaley A (2011). The impact of auditory distraction on retrieval of visual memories. Psychonomic Bulletin & Review, 18 (6), 1090-7 PMID: 21938641
Clapp WC, Rubens MT, & Gazzaley A (2010). Mechanisms of working memory disruption by external interference. Cerebral Cortex, 20 (4), 859-72 PMID: 19648173


  1. There's also the feeling of timelessness, not the poetic type, but simple fact that no clocks or natural sunlight are ever seen.

    I hear that a new trend is to introduce visual obstructions, walls and such that serve no purpose except to get you to ask,"What's around this corner ?"

    1. That's a great point! Can't believe I forgot to talk about sleep and circadian rhythms and stuff. ::headslap::

  2. Diane14:50

    Interesting timing of this post. I was just noticing this past Friday that working in the OR (during 2 back to back neurosurgery cases) is a lot like Vegas - minus the free drinks! Super cold air conditioning, bright fluorescent lighting, a losing track of time and of the outside world.

    1. Well, those things keep you awake and engaged, huh? I wonder if there have been any studies looking at ways to affect surgeons' wakefulness by manipulating their OR environment...

  3. White and gold colors don't have anything to do with any silly Wheel of Emotions. They are silver and gold. I used to live in that area (but across the state line), and silver and gold are just primal concepts stamped into the minds of everyone who lives there. That said, I felt like vomiting every time I went to Nevada, because it is not just the casinos that are set up to manipulate your brain, it is everything, down to the gas stations.

    1. Well, I wouldn't go so far as calling it "silly". The guy was a pretty prolific researcher. While I can't vouch for the truth of his research, the connection between color and emotion is fairly well established at this point.

      But yes, Nevada is a very unique place.

  4. Don't forget good old operant conditioning and the random reinforcement paradigm which encourages persistent playing. Much like a rat pressing a bar for food pellets, really. Depresses the hell out of me when I watch.


    1. Oof, yeah. That was sort of the point I was getting at about creating a game with lots of little wins for the player, but the post got way too long.

      It's definitely disheartening sometimes... Vegas only works for me if I turn my brain off and don't think too hard about what's going on around me.

    2. Anonymous02:58

      Do people really avoid boring games? There seems to be a lot of debate at the moment about whether blockbusters like FarmVille are actually fun. There's a whole category of "grinder" games which seem to suggest that many people are happy to play boring games.

  5. You lost me at "conjecture". There's been a lot written about this sort of thing. You shouldn't - and don't have to - just make it up.

    Also, a lot of your discussion seems strained, and your illustrations are actually counter-examples. Tables are rounded (none are actually round) because the dealer or croupier has to be able to reach all the bettors easily. Chairs are not necessarily round - all of the chairs in your photos are straight-backed. Of the three distinct playing areas illustrated in the photos above, only one has circular patterns on the floor. Betting chips are not always round - in European casinos they are often rectangular. (Though round ones also bear an obvious resemblance to coins, and to the kinds of tokens that used to be used in bars and brothels.) The first photo also makes it obvious that not all playing surfaces are green, so the color theory is out. (As for green, it was a traditional surface for card tables and pool tables before Vegas was ever a twinkle in Bugsy Siegel's eye. "The green baize table" was a euphemism for gambling at cards hundreds of years ago.) The noise and lights obviously play a role in creating excitement, but it's not clear they are intended to be distractions; the most abrasive gambling area is around the slot machines, where no decision-making is required, while the most sophisticated gambling games, though hardly subdued, are in quieter areas.

    In short, there seem to be obvious historical or functional reasons for the various patterns you mention, none of which are consistent in the first place. Your arguments are entirely of the type "this *could* be a reason", but you provide no evidence, and the visual evidence you do offer is in many respects the opposite of what you say!

    I can't really buy into this.

    1. Great points Kevin! I've added a note in the post itself to read your comment here. The historical reasons behind some of these things, while interesting, are a separate point. This post was to say what I would do were I to design a casino. I don't think the choices made are accidental.

      And to be fair, European poker chips are rounded rectangles, nor do I see where you see non-green playing surfaces. The slot machines don't exist in a vacuum, they are part of the overall ambiance of the entire casino. High-stakes games in secluded areas are a special beast--the House is more concerned about an air of sophistication than submitting their high-stakes clients to a raucous environment.

      But I concede your point.

      This blog is an exercise for me--it's a way for me to think about the world around me and interrogate what I see. It's pre-pre-peer-review. When I write, I get ideas and connect topics I wouldn't have thought of.

      And I get feedback by yours to challenge what I say, and I value that a great deal.

      But man, if you didn't like this musing, you'd hate my zombie brain posts!

  6. greenlight23:06

    JFYI, that photo of the Venetian casino floor you have there is from the Venetian in Macau, not Vegas (hence the trad. chinese signs).

    1. Doh! Thank you. Fixed with an update!

  7. Benjamin01:34

    There are also more sophisticated things casinos do, e.g. harrah's is providing it's customers with some kind of card in order to know how much they have played, lost, etc. They are mining this data for information and figured out some patterns of when a customer is likely to quit because of a bad strain, or when he is "too" successful at the moment, in either case, the customers are offered a free meal, or a drink, or some other distraction to get them to pause playing and continue later. Very interesting stuff on data mining applied in casino's can be found in "competing on analytics" by Davenport.

    Among other, at least nefarious, practices some casinos use, are, allegedly, trust-inducing pheromones which are pumped into the casino air.

    1. Trust-inducing pheromones? The chemist here wants to know.

  8. Casinos don't have windows so people lose track of time.

  9. Anonymous02:45


    There is a connection between colors and emotion but what is not proven is that this relationship is so fixed for every color(terror with green?, give me a break). Of course blood is red, sky(and water reflection and shallow ocean water) is blue and grass is green, but death is black in west and white in east.

    What is clear is that they use gold and silver(witch is not color at all but a mirror), and red. Brilliant and shiny and hot colors are related to anxiety and excitation. They use green as a contrast to orange not as the main color, but as a complementary. Shiny means it is constantly changing with small movements of the observer.

    But if you live in the Sahara desert, yellow and orange and reds means total relaxation while green means activity.

    Green uses to mean for people in western societies relaxation and is the reason the surgery and hospital rooms are painted green or light blue, but if you have a bad experience there you will hate those colors(like my father that almost died there because of a medical mistake).

    People develop anchors connected to their environment. I think what they really want is to make you feel completely stranger (alien environment) and break any connection to the outside, like sect cult do, if you go in group trying to isolate you physically or psychologically, you always facing someone from the casino(a person or a machine).

  10. superjoe02:49

    I'm sure the barely dressed dancers help out with the distraction too.

  11. Casinos also tend to slope inwards towards the middle, the reason they are like a maze is people tend to get lost and the mind will usually make us walk downwards if we feel we are lost or confused. Moving down will of course move us into the centre of the casino allowing more and more of the little tricks and sounds and colours to take effect

  12. Anonymous08:21

    You can add to the list of distractions that are designed to give the "house" the greatest advantage:
    Whitney Houston
    Amanda Knox
    Final Four
    4G Vs. 3G
    Anything Trump

  13. Anonymous08:50

    > Again, this doesn't have to be true, just /good enough
    > on average/.

    If you think about it, that's a pretty strange use of the word 'true'.

  14. Anonymous09:18

    It seems that you forgot to mention that casinos pump pure oxygen into their air ducts to keep gamblers from getting tired and wanting to go to sleep once they get drunk.

  15. Most casinos also display a list of winning Roulette numbers to trick you into applying the "law of small numbers" i.e. encourage you take erroneous intuitions about the laws of chance. In particular, they project last 10 winning Roulette numbers as highly representative, that is, similar to the population in all essential characteristics and bet on these "patterns". Amos Tversky and Daniel Kahneman have a paper in A Handbook for Data Analysis in the Behavioral Sciences http://amzn.to/Alqz4Z called "Belief in the law of small numbers"

  16. Anonymous11:00

    The garish carpets are supposed to play their part in keeping your eyes on the prize while moving around the hotel..

  17. Anonymous16:55

    I'd say that they use speed of play and intimidation as a factor to produce poor decision making as well. I remember the first time at a BJ table, they deal so fast and sit and stare at you while you add the cards and try to make the correct choice. All the while feeling terrible for holding up the game.

    1. Anonymous21:50

      I've had exactly the opposite experience, in that a majority of the dealers went out of their way to seem like they were gracious hosts and the player's friends... make the marks feel more comfortable, and they'll stay longer and spend more.

  18. I watched as a woman selected a particular color for her living room and the paint salesman asked her if she was sure. When she asked what he meant, he said that she'd be back in to buy new paint within 3 to 6 months. He said yellow is the most monotonous paint color and that everyone who paints a room yellow repaints it within a few months. These would be the colors of "joy" and "serenity" on the chart. My business and my home are painted a green, somewhere between "acceptance" and "trust" which is funny because we had a double color pallet last time of part "rage" and part "terror". I seem to lose interest when I'm in a room of between "anticipation" and "interest".

  19. Newish stuff on gambling/ casino behaviour from Journal of Gambling Studies, International Gambling Studies, Psychology of Addictive Behaviors, etc.

  20. This is an actual design problem in architectre and the leading books on the topic cost a heafty pile. I studied some of it for my thesis (city design in mmorpgs) and from top of my head I can tell few other tricks used:

    To distort the sense of space and time, corners of the rooms are darkened, routes are labyrinth-like there is no natural light nor visible clocks. Player is not supposed to notice how late it gets, and getting lost in the playroom is encouraged.

    To get the player to use as much as possible time in there, one usually has to go trough the gamling area to exit the building, enter the hotel or to use any attached services.

    Vibrant colors of carpets are made with purpose of making dropped chips hard to find. Scooping up chips from the floor at the end of the evening brings small revenue.

    Air is adjusted with fragnances meant to relax the visitor.

    Different machines have different profit margins - to enhance the mood of "people are winning here", most visible machines (on raised platforms, visible corners, etc) are adjusted to give out more. Makes also sense as these will signal the distracting sound-and-light shows most effeciently.

    After getting to know how much design-work is used in modern casinos, I've grown curious to experience this kind of environment using every trick confuse and disorient, while keeping visitors feeling relaxed, trusting and excited. Luckily I don't gamble.

    1. Fascinating. In mmorpgs, do they make it appear "brighter" if people are playing late at night to trick them into thinking it's earlier in the day? I've never drawn the parallel between gambling and mmorpgs before, but it makes perfect sense.

  21. David08:10

    I lived there for 15 years, and if there's one thing I learned about Vegas in that time, it's that it takes a lot of discipline to handle money with reason and not emotion, and everything about Las Vegas is geared towards a breakdown in discipline, a breakdown in taking responsibility for yourself and your actions. Most people, of course, don't take this to the extreme, and use Vegas as an excuse to let loose some inhibitions for a weekend, lose a little money (hey, the cost of having some fun right?) and go on with their lives. The problem is, like anything else in excess, people can lose their control to a point where it becomes detrimental to their health, financial and otherwise. Of course Vegas is designed to do what it does, and of course there are psychological reasons behind it. But while everyone's psychology works basically the same on the most fundamental level, the range of what their psychology can handle is as different as each individual one to the next.

  22. I'd pretty much expect the colors (they do that with fast food chains as well), but I didn't expect the shapes to be a factor in making a non-player want to learn to play poker.