A Magician’s Best Trick: Revealing a Basic Human Bias | Hacker News Reader

A Magician’s Best Trick: Revealing a Basic Human Bias

wsj.com

220 pointsanigbrowl63 comments

James Randi did a similar trick, i.e. one even less reliant on mechanical tricks or a quick hand but rather on human bias.

Students in a class were given horoscopes in envelopes marked with their birth dates. The students were then asked to read the horoscopes and tell if they were accurate. Most were amazed how accurate the horoscopes were.

The trick is that every student had been given the same horoscope which was just cleverly written.

Video here: https://www.youtube.com/watch?v=3Dp2Zqk8vHw

This is a demonstration of the fallacy of personal validation. (And yet personal validation is brought up in dozens of replies on Hacker News each day.) That demonstration of the fallacy of personal validation was first made by psychologist Bertram R. Forer (1914-2000), who published a paper about the experiment in 1949.[1] Because Forer was the first to publish about an experiment on the issue, the phenomenon is sometimes called the Forer Effect.[2] The fallacy of personal validation is one of the bases of the practice of "cold reading," pretending to read someone's mind by throwing out wild guesses and observing which wild guesses are accepted by an observer.[3]

[1] http://apsychoserver.psych.arizona.edu/JJBAReprints/PSYC621/...

[2] http://skepdic.com/forer.html

http://badpsychologyblog.org/post/33441629830/the-forer-barn...

[3] http://skepdic.com/coldread.html

http://denisdutton.com/cold_reading.htm

At an early web development job, I was in a pitch meeting for a horoscope website where the designer of the "system" asked for my birthday. I told him Oct 1st and he preceded to do his calculations and how it showed that I was obviously a leader and people looked up to me, and how it was so insightful etc. Only problem was that I was actually born on July 6th.

During the development of The Sims 1, Will Wright came up with the idea of assigning each of the Sims a Zodiacal sign, based on the personality points that the player "spent" on them on the character creation screen. He defined 12 different archetypal sets of personality point values, one for each sign, and it simply assigned the nearest sign to the character's current personality.

Some of the other designers argued that we should come up with our own fictional astrological signs for the Sims, since there was already so much baggage associated with the traditional ones. But Will countered that the baggage was the whole point!

So we implemented the design for assigning astrological signs in the character creation screen. But at that point, the assigned signs were purely cosmetic, and had absolutely no influence on anything else in the game.

Then we let the testers take a crack at it, to make sure there weren't any bugs in the character creation screen.

Of course the testers immediately started reporting problems that the character's astrological signs were effecting their behavior too much, and that the game needed to be tuned so that their signs did not influence their behavior so heavily.

That's exactly the kind of behavior that Will was trying to influence by using "real" astrological signs, along with all their glorious baggage and preconceptions: the behavior of the player's mind, no the behavior of the game itself! It anything needs tuning, it's the player's belief in astrology.

If you enjoyed this you might be interested in reading up on James Randi. To quote Wikipedia, he is "a Canadian-American retired stage magician and scientific skeptic best known for his challenges to paranormal claims and pseudoscience."

There are numerous documentaries and films about him and his life, the one that got me started was a BBC Storyville episode: http://www.bbc.co.uk/programmes/galleries/p029bgws

It's not currently available on iPlayer apparently, though that restriction does not apply to torrent sites. Couldn't recommend it enough.

Small snippet of a show of his (old) https://www.youtube.com/watch?v=AfZDwDE1yr8 Just for fun, the chair drop was priceless.

There is an award winning documentary on him released recently - "An Honest Liar".

    http://anhonestliar.com/

I just finished reading "Thinking Fast and Slow" by Kahneman. He goes into great detail about our various cognitive biases, and how they constantly lead us astray. The most fascinating insight is how they still lead experienced statisticians astray in the same way, and even when these biases are pointed out to them! The mistakes keep coming.

We're not half as intelligent and rational as we believe we are.

I'm having a terrible time with that book. It's so incredibly dry!

I found it terribly repetitive.

Phew, I'm glad I'm not the only one. I initially blamed my short attention span.

Very repetitive, and very dry. You could have said all of it in significantly less time.

I started with the audio book on a long drive, and it was enjoyable because I had nothing better to do, but I'd have never listened to it without driving a long way. :)

I have it and I'm considering it my next read but this sounds bad. Does anyone have a different opinion?

Yes. I couldn't put it down.

I've not read it yet, but have read Heuristics and Biases, which is Kahneman and Tverskys original research on the topic. It is very long and sorta dry, but incredibly useful. I'd also suggest reading the LessWrong sequences on rationality, as they are aimed at actually helping you be able to change your mind.

I think people like it because it was seminal, and just about every other pop psychology book references it. That said, the material is better presented elsewhere. A great book that I enjoyed is: http://www.amazon.com/Makes-Brain-Happy-Should-Opposite/dp/1...

It is probably not the greatest in terms of writing style, but : I read it in January 2013, and it is by far the most memorable book I've read the whole year. I still think back to it, whereas I couldn't tell you what I read in August.

I haven't finished it, but not because it's boring. It's one of those books where I feel I have to start over reading more carefully after a few chapters. Unfortunately that makes it likely to be procrastinated away. I'm determined to finish it this year, though.

Perhaps a better starting point would be the books of Dan Ariely, in terms of readability.

I only got a third of the way through it. It is interesting, but not really well written. There is no overarching narrative -- it's basically a collection of dry snippets. But the ideas are fascinating. I have every intention of finishing it.

Try Influence: The Psychology of Persuasion by Robert B. Cialdini. Its a very readable text on how bias can be taken advantage of.

Yes, that one is good too, but it covers different material.

I thought I was the only one.

Always great to hear a review like this! This is what I felt but I am surrounded by people who have read the book and have loved it.

"Buyology" and "How We Decide" are both excellent books on the shortcuts the human mind takes when making decisions or evaluating the environment in general.

Also, Nat Geo has a fun show called "Brain Games" along the same vein.

All suggestions are a little "poppy" for some tastes, but I find them all entertaining and informative, and have found many useful bits that I apply to my sales and training efforts as well.

I enjoy books like this, but they feel like entertaining books without much that is truly useful.

The one thing I love about magic psychology, which is a huge and complex field, is that the things they say are useful, and completely true all over the world.

Magic comes at psychology analysis in a different way, only what works through tried and tested outcomes. A Magician would never say they understand human psychology, and yet reading or listening to Magicians on human psychology has taught me more about it than any number of pop psych books.

I don't know what that means, but I understand human psychology leagues better from magic than I ever did from any book.

I think there are a lot of parallels between the "neuroscience" (quotes intended) in the books and psychology useful to magicians. The books both, for example, discuss both the psychology and the neurological activity surrounding the human brain's desire to find patterns, and rely on them for future "automatic" thought. The well known inability for a person to judge the volume of a container, for example, influences both consumers purchasing a bag of chips and a spectator watching a woman get sawn in half.

There are stories in "How We Decide" that are variations on stories in "Cruel Tricks for Dear Friends". "Buyology" anecdotes remind me directly of things I learned from reading Paul Harris.

To be sure, the books I mentioned are written to entertain as well as inform. They're "pop-science", and nobody would suggest that Jonah Lehrer is an authority on neuroscience - but that doesn't detract at all to their utility to anyone who can benefit from understanding how humans - even one's self - think.

"You are not so smart" by David McRane touches the same topic. It goes through the long list of ways we are fooling our selves or "not being as smart as we think we are". And for each case he is also referencing the studies proving this.

http://www.amazon.com/You-Are-Not-So-Smart/dp/1592407366

He also has a blog with the same name as the book that covers the same topics (I believe the book came out of the blog): http://youarenotsosmart.com

Magic is fascinating. Theres a magician that is in the first season on his tv show called Michael Carbonaro. The show is called the Carbonaro Effect. Basically, he sets up scenarios and goes on to fool people using magic. My favorite scenario that I saw was when he was showing people how to rebean ground coffee beans and the lady he was showing it to said, "Yeah I know how this works. I used to run a coffee shop."

The Carbonaro Effect is interesting because it isn't telling the person ahead of time that they are performing a magic trick. The trick is to have them believe a serious proposition in a serious place.

I dislike that it's a lie to the person to start. I do magic because I love to do magic, and want to share my passion with you. I don't enjoy lying or deceiving you in a serious manner like that.

But to each his own.

As an amateur magician myself, I've always thought of magic as "deceiving with the intent to delight".

The difference being, to me as an audience to your magic, is that I know that I'm being deceived and still delighted by it.

Well said, and point taken.

To add to GP's point, telling the audience they're being deceived makes the trick even harder to pull off. I'm sure many will run along with the trick, but some people like me will keep an eye on suspicious moves and, as GP said, still love to be deceived even when paying attention.

That's why I love up-close magic tricks and loathe magician TV shows full of cut shots and stooges in the audience.

EDIT: Either Criss Angel or Dynamo just downvoted me! :P

This is one reason I love Penn & Teller. They never insult their audience by claiming to actually have magic powers. It's hard to beat their cups and balls trick using clear plastic cups while explaining exactly how the trick is being done, yet it's still almost impossible to follow the sleight of hand for most people. It's so impressive.

Being deceived ~= learning, which we crave.

Also, he can get away with much simpler / basic tricks because people aren't expecting it. It's more of a prank that uses magic than the traditional magic as an art form.

Reminds me of this ancient web magic trick.

http://www.angelfire.com/ak2/intelligencerreport/page67.inde...

Only a person who doesn't know how the Web works will fall for that.

The "z-chip" thing is obvious crap but I read it as adding a (not necessarily believable) story to make the trick more interesting and misdirect you away from the truth. Not a scam someone would "fall for"

These comments tend to be very amusing.

So a scam is the only thing a person can "fall for". You can't fall for an interesting trick, eh?

No, you absolutely can, and I have. However many times a trick like this will have a completely unbelievable story. The point isn't to get you to believe the story, it's to distract/amuse you.

Think of it like a ghost story. In general you know it's not true but it gets your mind going.

You don't need to know anything about how the web works. The second set of cards they show you doesn't have ANY of the original cards, so there's a 100% chance that the card you chose will have been "removed". If you're only concentrating on the card you chose, you won't notice that all of the other cards have changed, since they look similar (8 of clubs turned into the 8 of spades).

See, I was assuming he meant that only people who don't know how to use the 'back' button to compare the two sets of cards would be fooled.

The real trick there is an Angelfire site still up and running

I forget who, but that magic trick was actually a shareware program years before the web, published by someone who is relatively famous since.

For a good example of confirmation bias watch Derren Brown's "The System" [1] where he makes a woman believe an unknown benefactor has a foolproof system for betting on horses. "Mail Order Prophet" [2] by Alfred Hitchock has a similar idea.

[1]https://www.youtube.com/watch?v=9R5OWh7luL4] [2]https://www.youtube.com/watch?v=zh0MvRagES0

Richard Feyman told a similar story about con man he met in Vegas. He talks about the probability computations needed to work out each step in the scam -- how the con man makes money off a "no-risk trial, I will pay your bet if you lose")

Mathnet on 321-Contact did the mail order prophet scam, and my dad's stockbroker friend once joked about running the same scam.

A mathnet reference, wow. My favorite show as a kid, I even show my kids it today.

Edit: Found the episode for you

https://www.youtube.com/watch?v=Tj-XMRu_q4s

Man, this just lead me to tracking down and watching every Mathman segment I could find.

I watched Square One so much as a kid and it directly inspired my love of engineer and math.

I love Darren Brown, but that particular con doesn't really exemplify confirmation bias. Confirmation bias is a selective willingness believe new information only when it conforms to your previous beliefs. The system is a good example of how a limited perspective can introduce those false beliefs in the first place - namely, when every horse you bet on wins, you start to think there's a system. But a the key part of confirmation bias isn't acceptance of information which fits your beliefs, it's the rejection of information that doesn't.

For a good example of confirmation bias by Darren Brown, in his videos on psychic readings [1], he throws a multitude of information out, and people latch on to information which confirms his psychic abilities, and ignore the rest, making his abilities completely unfalsifiable.

[1] https://www.youtube.com/watch?v=6_3L9lB1Qtg&t=2m18s

This article reminds me of some videos I've watched on YouTube about paranormal "investigations". It's kind of funny how prone the "investigators" are to interprete random events as paranormal manifestations. Background noises are generally seen as EVPs[1] and they manage to match them to something they were expecting to hear; [2] provides a reasonable explanation for that.

[1] https://en.wikipedia.org/wiki/Electronic_voice_phenomenon [2] https://en.wikipedia.org/wiki/Apophenia

The dime-in-both-hands trick is a very clear example, but it also sounds so simple and obvious that I can't imagine many people falling for it, especially if they knew the performer was a magician. But perhaps I'm just so cynical that I would always be more concentrated on figuring out a magician's tricks than letting myself be entertained.

It isn't a trick that I've ever seen a magician perform, it's more along the lines of something your Uncle would do.

Many people are more concentrated on figuring out a magician's tricks. A great magician will make sure you aren't particularly worried about that until the end when you go, "Shit, what happened?"

I'm a magician, and there are many extremely interesting parts about human psychology that relate to lessons you learn. This isn't one of them.

This is a fine fluff piece about someone's experience watching a magician (and not a particularly good one from the tale). Nothing wrong with enjoying the story, but it doesn't reveal anything particularly interesting.

The psychology of the spectator is the most fascinating part of magic to me. I'm not sure how it would relate to "diplomacy, politics, finance and everyday life."

I know I use the same psychology in social situations, and public speaking that I do in magic, at times. It's hard to generalize because magic is an amazing field of a ton of areas.

I want to tell you what it is, why I use it, and details about it because it's a passionate hobby of mine, but magic is also the only field I've ever known where you aren't allowed to share what you do.

You build up a tremendous amount of skill, and then hide it. Guitarists show you what they do, amazing. Artists, Actors, Jugglers, Comedians..

Magicians are the only one where success is hiding your skill.

This is a fine fluff comment about someone's experience reading about a magician. (And not a particularly good comment.) Nothing wrong with making a comment, but it doesn't reveal anything particularly interesting.

In all seriousness, I get that you don't want to share secrets. But your tone comes off as just acting superior without any substance behind it.

I also wonder what you mean by "you aren't allowed to share what you do." Is there some enforcement entity that will come get you if you share? Will Penn take you into a dark room and sit on you or something? Or is just a behavior that all magicians adopt for the shared success of the group?

You're one to talk about tone.

> I'm not sure how it would relate to "diplomacy, politics, finance and everyday life."

Spinning narratives that reinforce what people want to believe has been a time-honored tradition since the beginning of humanity. It's deeply relevant to those domains and more.

> Magicians are the only one where success is hiding your skill.

Magicians are one of the few crafts where hiding skill is mandatory (perhaps barring meta-showmen like Penn & Teller).

But this pattern too shows up many other places. Comedians have to conceal the performative nature of their act, making it seem like the 874th iteration of a joke is something they just thought of extemporaneously. Actors aren't eager to share the mundane grind of their method(s), so as not to break the illusion. (For instance: Tom Hanks sometimes does math problems in his head for certain types of reaction shots.) Or consider the politician backed by the talented speechwriters and research team, who you'll never meet or even hear mentioned.

In a sense, stage/street magic is a subset of a game that all humans play: perception management (with varying degrees of honesty). Being more aware of this process and how our buttons are being pushed is something that would help us all.

Very good point about performers hiding the mundane method of their grind. But the actual performance shows the skill. Magic hides the skill.

Anyone interested in the neuroscience behind magic should read Sleights of Mind http://www.sleightsofmind.com/. Really fascinating book!

This is the same con used in the classic three card monty.

This is a great "prank". Anyone know of any similar ones? I don't even know what to call the genre. It's more mind bending than pranky.

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