One of my favourite aspects of the show was the way he was able to explain how improbable events happen all the time, given enough opportunities.\u00a0 At one point, he asked everyone to stand up.\u00a0 Straight away, he asked all the men to sit down.\u00a0 Next, he told all the women not in the 25-35 age group to sit down.\u00a0 After a couple more such reductions, the people left standing were women aged between 25 and 35 who had a dog (or dogs) and at least two tattoos.\u00a0 If you were a 30 year old, female, dog owner with several tattoos, you\u00a0might feel a little spooked\u00a0at this point – like Derren personally\u00a0selected you from the crowd.\u00a0 At this point, however, the lights came on, and everyone was amazed at how many people were still standing (well, everyone except the mathematicians).<\/p>\n
But the lesson is simple.\u00a0 If there is a 1\/100 chance that a typical person off the street is a woman aged 25-35 with a dog and a few tattoos, and if you have 2000 randomly selected people in a room, you\u2019d expect around 20 of them to fit all the criteria (the audience was about 1700 strong, and there were a few dozen people left standing).\u00a0 But if you were one of those people, and you hadn\u2019t thought about the numbers, you\u2019d be feeling\u00a0pretty special.<\/p>\n
A while ago, I heard of another case that illustrates the same phenomenon, perhaps even better.\u00a0 Suppose you\u2019re looking through your email inbox, and you come across a message from a self-described sports tipping expert.\u00a0 She tells you Team A will beat Team B in a match on the weekend.\u00a0 You promptly go to the next email and forget about it.\u00a0 Next week, you get an email from the same person saying that, this weekend, Team C will tie with Team D.\u00a0 You think back to the previous email and look up the scores and, sure enough, Team A did beat Team B as the expert predicted.\u00a0 So this time you watch the game between Team C and Team D, and it does indeed end in a draw.\u00a0 This same pattern happens for another three weeks \u2013 you receive a prediction before the game, and the expert\u2019s tips always turn out to be right \u2013 five correct predictions in a row.\u00a0 By this time, you\u2019re impressed.\u00a0 The next email you receive from the expert says:<\/p>\n
\u201cYou\u2019ll no doubt have noticed that I\u2019ve now correctly predicted the outcomes of five matches in a row.\u00a0 I didn\u2019t just pick the favourites, though \u2013 some of these results were big upsets, so you can see I am highly skilled in the art of sport prediction.\u00a0 If you had bet $100 on each of the matches, you would have made a profit of $1,000.\u00a0 I can continue to send you my predictions for the remainder of the season, but you will have to pay for my advice from now on.\u00a0 You can keep receiving my tips for a modest up-front fee of $200, payable to…\u201d<\/p>\n
So you send off your $200, and now you\u2019re really excited about the money you\u2019ll make.\u00a0 How lucky you are to have discovered, quite by accident, such a useful source of reliable information!\u00a0 So, you make a few bets, following the expert’s predictions for the next few matches.\u00a0 But suddenly, the predictions are not so great.\u00a0 You find you\u2019re winning some and losing some, and not really doing any better than you would if you relied on your own (far from expert) judgement.\u00a0 So, what happened?<\/p>\n
Here is what happened…<\/p>\n
When you received your original email, another 1,000,000 people received exactly the same one.\u00a0 Another 1,000,000 received an email identical to yours except predicting that Team B would beat Team A.\u00a0 A further 1,000,000 were told that there would be a draw between Team A and Team B.\u00a0 After the match (in which Team A beat Team B), the second and third groups of 1,000,000 never heard from the \u201cexpert\u201d again.\u00a0 Then, the first group of 1,000,000 were split into three groups.\u00a0 The first group were told that Team C would beat Team D, the second that D would beat C, and the third that the game would end in a draw.\u00a0 Since the game did end in a draw, the first and second groups never heard from the \u201cexpert\u201d again.\u00a0 The same pattern was followed for five weeks.\u00a0 At the end of the first week, the original target of 3,000,000 was cut down to 1,000,000 who had received the first correct \u201cprediction\u201d.\u00a0 At the end of the second week, approximately 333,000 people had received two correct predictions in a row.\u00a0 After three weeks, 111,000 had received three correct predictions, then 37,000 after four weeks.\u00a0 Finally, after five weeks, more than 12,000 people had received five correct \u201cpredictions\u201d in a row.\u00a0 And imagine now if just 1% of these people signed up and paid their $200.\u00a0 The \u201cexpert\u201d would pocket about $25,000.\u00a0 And all with absolutely no skill whatsoever.<\/p>\n
The moral of both stories should be clear.\u00a0 If some outcome has a 1 in X chance of happening, and a group far bigger than X has the opportunity to achieve the outcome, you can expect the outcome to occur several times.\u00a0 People win lotteries, and people recover from \u201cincurable\u201d illnesses.\u00a0 \u201cAlmost certainly not\u201d does not mean \u201ccertainly not\u201d.\u00a0 A one-in-a-billion day happens to around 7 people every single day.<\/p>\n
Well, I was thinking about this as I was on the bus to the airport this afternoon, about to head back home.\u00a0 And as we drove past a church, I noticed a big sign saying\u00a0Try Praying<\/i>.\u00a0 The idea is obvious.\u00a0 If you\u2019re a skeptic, why not just\u00a0try<\/i>\u00a0praying?\u00a0 You\u2019ve really got nothing to lose, right? \u00a0If there really is no god, then obviously nothing will happen, and you\u2019ll have lost nothing \u2013 just a few seconds wasted, praying to an imaginary deity.\u00a0 But if there really\u00a0is<\/i>\u00a0a god, your prayer might result in something amazing \u2013 you might get that promotion you\u2019ve always wanted, your mother might recover from her illness, you might restore your relationship with your estranged family \u2013 the possibilities are endless. \u00a0(And then I suppose you\u2019d start attending that church.)<\/p>\n
But think about it.\u00a0 Imagine if every resident of Edinburgh prayed a very specific prayer.\u00a0 Suppose they all prayed for some event to occur, an event with, say, a 1% chance of happening.\u00a0 Well, the population of Edinburgh is about 500,000.\u00a0 So you\u2019d expect a total of 5,000 unlikely events occurring (seemingly) as a direct result of prayer.\u00a0 That\u2019s a lot of \u201cunexplainable coincidences\u201d!\u00a0 And if everyone prayed for\u00a0several<\/i>\u00a01% events, then the list of \u201canswered prayers\u201d would be very long, indeed.<\/p>\n
But nothing would have been proved about prayer at all.\u00a0 If the Edinburghians prayed to Zeus instead of (presumably) the Christian god, the same number of desired outcomes would have been achieved (still by chance).\u00a0 Same with Allah, or the Flying Spaghetti Monster.\u00a0 You can even pray to me if you want \u2013 tell me what happens!<\/p>\n
But, to the person whose son learnt to walk again, despite being given a 1% chance of ever getting the use of his legs back, it can seem like something truly special has happened.\u00a0 Such people will most likely end up in the pews of the local church, telling their amazing story for the rest of their lives, and providing others with a great \u201creason\u201d to believe in God. \u00a0In the meantime, for every such lucky family, another 99 sons are still in the wheelchair.\u00a0 The trick didn\u2019t work for\u00a0you\u00a0\u2013\u00a0you\u00a0weren’t selected, and you can sit down, now.<\/p>\n
So, next time something unlikely happens to you, don\u2019t assume it must be for a reason \u2013 it probably wasn\u2019t.\u00a0 Just remember that if enough people try and achieve something unlikely, someone\u00a0will<\/i>\u00a0achieve it.\u00a0 It\u00a0has\u00a0to be\u00a0someone<\/i>, and it just happens to have been your turn this time.<\/p>\n
![\"hands\"](\"https:\/\/skepticink.com\/reasonablyfaithless\/files\/2014\/07\/hands.jpg\")
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