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  • 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.

You've watched that coin flip nine times.

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B1 UK TOEIC probability gambler fallacy fifty percent thunder

Critical Thinking Part 5: The Gambler's Fallacy

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    賽魯 posted on 2015/04/23
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