Critical Thinking Part 5: The Gambler’s Fallacy

Critical Thinking Part 5: The Gambler’s Fallacy


You’ve watched that coin flip nine times.
Heads, tails, then heads again,
then tails, tails, tails, tails, tails, tails.
And, what’s going to come up next?
Tails has been having a pretty good run,
so it must be another tails.
Or are we due for another heads?
There are patterns everywhere in the universe,
and our brain is very good at recognising them.
Perhaps too good.
It can readily see patterns that just aren’t there
In truth, there is a fifty percent chance of heads
and a fifty percent chance of tails, after every toss.
It doesn’t matter what came before,
and luck doesn’t come into it.
At all.
But it’s hard to shake that feeling that
there’s a pattern in there somewhere –
if only we look hard enough.
This is called the Gambler’s Fallacy.
Our assumption that probability changes,
depending on past results.
And this may explain
why casino’s make so much money.
It’s all a matter of probability, one of the more
complicated forms of logic.
In fact it’s so complicated,
it was only a few centuries ago that some
smart French chaps by the names of
Pascal
and de Fermat,
worked out much of the mathematics
behind it.
Our brains make it difficult for us to see
the logic in probability and lead
us astray.
We’re wired to link the things we see
as if they’re related.
For example, seeing a flash of lightning
and hearing a boom of thunder
makes it seem like as if the thunder was caused
by the lightning.
And there are plenty of reasons
to believe that’s true.
But what if you ate a hotdog and then got sick.
Was it the hotdog, or was it something else entirely?
Medicine is full of such head scratching
questions. People take pills and feel
better.
But a lot of logic and probability is
needed to determine whether the pills were
truly responsible. Just because one
thing follows another, even if it happens a
few times, does not necessarily mean that
they’re linked. There could be other
factors, or it could simply be
coincidence.
To know for sure you have to test the
circumstances again and again,
looking for those other factors that could
disprove the link.
This reinforces confidence that your pattern
is true.
This is what science does.
So while our brains see patterns, and this is often
very useful, it takes science to prove
that these patterns are real.

75 thoughts on “Critical Thinking Part 5: The Gambler’s Fallacy”

  1. "So while our brains see patterns,…it takes science to prove that these patterns are real."

    Awesome line. Keep them videos coming!

  2. I had a Reese's Peanut Butter cup once, and got a throat infection the next day. never ate them again, even though I liked it.
    Same fallacy I think.

  3. Very true, but if I toss a coin 99 times the probability should be close to 50/50 or else there is some external influence. If I get 98 tails,out of 99, while not impossible, this is highly unlikely, and in such a case, its hard to say, but I would be right to assume that the law of probability will be satisfied at some point, and start picking out heads, because its more probable that heads will show up, then that the stupid simple coin will break the laws of probability and give me more tails.

  4. @jnwpse Or you're related to Erik Lehnsherr and need to band with others who can inexplicably alter the laws of probability as well.

  5. @TinQuasimodo I considered magneto being in the area. I also considered shooting him if so, so as to get my reality back. But it hit me, the guy can really stop a bullet cant he? So I set out to master the kamehameha wave, which he has no influence over, considering this is pure ki. When I first started it was quite messy really. Goku makes it look so easy. You have to be as still as a rock when executing it, which was a task in and of itself, seeing as the thing has much leverage.

  6. 0:40 "just aren't there"… all the patterns we see are constructed, and are real, in our minds. What you mean is that only some of them tell us something useful about the world.

    0:45 "50%". You are assuming an ideal coin, and ideal coin flipper, which you did not state. You need to factor in the chances that the coin and/or flipper may be biased, and by how much, and for what reason.

  7. @Neoplantski Probability doesn't work that way. With 100 perfect coin flips, the odds of it being EXACTLY a 50/50 split is about 8%, assuming my math is right. I think the formula is (n choose n/2)/(2^n), n being 100. 40 heads and 60 tails is about 1%, and the probability of it being BETWEEN 60/40 and 40/60 is about 96.5%.

    The trick is that as n grows arbitrarily large, the standard deviation, as a FRACTION of n, becomes arbitrarily small.

  8. @MrBoo88 "I can't decide, maybe I should flip a coin, hope it explodes and kills me" – Black Books. (can't say it couldn't happen either).

  9. @vgmjbpkcdmqd But this is an event in an event, you know what I mean? You flipping a coin 100 times is one event that has its own probabilities. And then each coin flip has its own probability which is exactly 50 50. Does that make sense?

  10. @vgmjbpkcdmqd You'd be pretty vexed if you flipped a coin 100 times and got 98 heads. You would expect roughly 50 50. This is the reason Carl Sagan says its unlikely that we are alone in the universe.

  11. @vgmjbpkcdmqd You make it sound like I'm trying not to be proven wrong or stupid. I thought we were having a normal conversation here, if I'm wrong so what? I'm not trying to be right or prove you wrong at all. Just trying to get something clear. Anyway, I see what you mean and agree that it has no effect on future result. The last coin flip has nothing to do with the next, but what I'm saying is the net coin flips, have a probability of 50/50.

  12. Resently I read Dostoyevsky's "Gambler", and it was funny how well the gambler's fallacy was portrayed in it, BEing a gambler himself, Dostoyevsky probably did believe himself that only a stupid gambler bets on a zero, after making a killing on it, when a smart gambler knows the zero isn't due for a while.

    However casino's make money because people believe they can outsmart the odds. Gambler's fallacy is a small part of it.

  13. There's a premise flaw in the argument over what coin toss result to expect next. Seeing 7 out of 9 "tails" results brings one to suspect that the coin is not fair after all and that the odds are greatly in favour of another tails. Pattern recognition is a tool by which we can determine probabilities in real world situations, and in fact this type of inductive reasoning is the basis for a lot of science.

  14. @Alexthebling For a conventional flat-disc type coin, any weight "on one side" will also be on the other, unlike with a six-sided die (for example). So actually making a trick coin is much harder than that. Most coins in most countries are fair.

  15. In the real world, yes. For the sake of argument and demonstration, as here, one has to assume or agree that the coin is fair.

  16. Great video! I work in PR for an online casino, and people are always asking me if this or that "betting system" will work. Betting systems actually exploit the gambler's fallacy because they tell people to bet on the expectation that a certain outcome is 'due' in roulette, craps or slots. If only people thought a bit they'd realize that if a betting system could beat the house, casinos would go out of business in a flash!

  17. Getting permission to have them redubbed is tricker, but we'll keep your request in mind and will let you know. Thanks!

  18. I'm a professional translator and I'm currently working on translating the series into Russian for the people from the Zeitgeist movement. It'll be completed in a couple of days. If you wish, I can contact you when I'm done and send the text broken down into same pieces as they appear in the video. I read my YT PM regularly, so you may reply there directly.

  19. Though it's hard to admit, in the end we don't even know that cause and effect exist. There are quite a few things like this everyone assumes; otherwise we couldn't have science.

  20. There's no way I'm the only one who saw a swastika in the stars. Maybe that's 'cause that's what I always see…

  21. Don't be so hard on yourself though. Part of that was likely instinct, which is an unguided process. Blame the fallacy on natural selection. 😛

  22. Cause and effect is one of the most fundamental observations of the universe and is the basis of all the laws of physics, everything that exists in the universe and everything that has happened and will ever happen. If you're taking the position that nothing can be known for certain, then sure, cause and effect might not exist, the universe itself might not exist, we might all be dreaming right now etc.
    But if you're genuinely skeptical about cause and effect then you might as well know nothing.

  23. I agree, I was just pointing out that it generally makes more sense to speak of probabilities than certainties, since correlation can never truly prove causation. This is why scientific theories are called "theories".
    It makes sense to assume such fundamental things are real as, if nothing else, a methodological assumption. Thinking any other way would lead to solipsism.

  24. Actually there is more like a 49.9% chance of tails. 0.2% chance of it landing on the the edge, unless forced to a down position.

  25. If you flip a coin 99 times and it always comes up heads, what is the probability that it will come up heads on the next flip? The statistician will tell you 50%. At some point you have to start believing that the coin isn't perfectly balanced.

  26. Reason I say this was because I was messing around tossing a coin I chucked in the air on to my table it landed on the table, started to spin, then stopped in the up right position. It was awesome.

  27. For each individual coin flip the chance is 50 50. However the odds of getting heads heads heads heads heads heads heads heads is very low. So I guest its how you luck at it.

  28. I'd say there is a greater chance the coin would land tails.
    When I was a kid I developed the skill to dictate the results of my indoor coin flips to an accuracy greater than 95%. It all boiled down to precise muscle memory and subtle tricks.

    If you pay attention to the side the flipper starts on each time, a flipping habit could skew the 50/50 probability, for instance:

    When the flipper starts on heads, it lands heads.
    When the flipper starts on tails, it lands tails.
    He naturally rotates the coin when placing it on his thumb causing a 'heads-tail-heads-tail' pattern however, the individual probability for each flip is not 50/50.

    If I expand on my initial statement I'd want to say there is a greater chance the coin would land tails, but in all honesty I'd have to be there in person to make my prediction.

  29. this reminds me of the monty hall problem.
    why it gets constantly misunderstood is because of the gamblers fallacy, what this guy talks about here..  only now,  ive been able to put it into words.

  30. flipping a coin never seemed like a good example to me…you could just get used to flipping it with such finesse and precission that it will always land heads/tails….so its not

  31. This series would be useful if it wasn't so obviously geared towards attempting to convince people of politically correct narratives such as Global Warming, Evolution, Vaccinations and such.  It's presented as a way to think logically and in an unbiased fashion but subtely, and deceptively, it places these subjects in the midst of logical discussion, presenting them as fact, without actually discussing the logic and science behind them.  Disappointing

  32. Very interesting phenomena. Talking about the medicines, I took this medicine that improves mental focus, I surely felt some difference. This medicine is awesome in improving physical and mental performance for me. Have a look at it

    http://www.amway.com/Shop/Product/Product.aspx/Nutrilite-Rhodiola-110-Dietary-Supplement?itemno=101593&pwsID=AbishaiSingh

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  33. it's actually pretty arguable that this is a fallacy to an extent.

    obviously the idea of being on a roll is a fallacy, however, i would argue that getting the same result multiple times in a row on a 50% chance is less likely than getting mixed results.

    for example, if you had just decided you will flip the coin 10 times, it is extremely likely that both results will show up at some point during the 10 flips. the odds of only one result showing up consecutively for all 10 flips is extremely low.

    the idea is not that each flip of the coin lowers the chance of it landing on a specific side. it is always a 50% chance. but getting the same result from a 50% chance several times in a row has a separate percentage chance that needs to be calculated. flipping heads twice in a row has a 25% chance of happening. this is not a 25% chance of getting heads on a second flip, but rather a 25% chance overall, for both of the flips. this is because you are combining two 50% chance actions.

  34. Casino's don't make money because of the gamblers fallacy. That is quite a poor example. The gamblers fallacy would set the casino to break even after a long period of business (assuming non-skill based games). Casino's make money because the odds of the games are in their favor (and other sketchy tactics).

  35. I generally consider myself as a rational thinker, but this thing almost always goes against my intuition despite the fact that I know it's wrong.

  36. Forgive my ignorance but.. wouldn't using repeatable evidence and the scientific method to try to discover the patterns in the universe also be the gamblers fallacy?

    Sure, everything in science might seem true now, but.. that's just because we were lucky. If we were to test the same experiments another 1,000,000 times, according to the gamblers fallacy, we could possibly get a different result.

    Can anything ever truly be predicted? If our intuition works so well, and yet things are ultimately unpredictable..

    …Mind blown.

  37. To be slightly more accurate: you have a 50% chance of winning a coin toss, *assuming that the coin is evenly weighted*. If tails appears to be doing improbably well, it is possible that it is doing so because the coin was not evenly weighted, and your assumption was false.

  38. You defined the fallacy well . . . But I wish you would have disproved it rather than go off on a tangent about the history of probability.

    The part that got me was understanding that the probability of flipping H H H H is equal to H H H T

    So while, yes, it’s very unlikely to flip 10 heads in a row; it’s equally unlikely to flip 9 heads and 1 tails!

  39. "our brains are too good at seeing patterns, it sees patterns that aren't there"

    That's not being good at seeing patterns, that's actually bad at seeing patterns. Our brains are bad at seeing patterns.

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