What Are The Chances?

"What are the chances of that happening?" - Harry Hill

Many years ago, a lady called Pat was on her honeymoon in the beautiful Slovenian town of Bled. One night she had a dream about two old friends of hers, Hilda and Stella. It wasn't particularly remarkable but, as happens in dreams, it was a bit of a reminder of two people she'd not seen for over two decades - and had barely thought about.

Two days later, while visiting the castle in the middle of Lake Bled, Pat looked down to the tier below and who should she see walking along? You guessed it, Hilda and Stella. Was this an example of dream precognition or was it simply a massive coincidence? Professor Chris French's talk, The Psychology of Coincidences, last night at Greenwich Skeptics in the Pub at The Star of Greenwich delved, both seriously and humorously, into this world and made for a very enjoyable evening.

For me, personally, it was a tonic after a few weeks in which the anxiety I have long suffered had started to become almost unbearable. Chris French is always an excellent speaker and with a book to plug, The Science of Weird Shit, he's doing the rounds a bit these days. In fact, once he'd told the story of the Bled Castle catch-up he was on to a story from his own book.

I clutched my blackcurrant and lemonade and listened in. Chris told of his sister-in-law (who was present in the audience, along with her dog Ted) returning from a Greek island and relaying to him a story of a friend on that Greek island finding a ring on the sea bed that was, in Greek wedding tradition, inscribed with both a name and a date.

A woman approached the finder of the ring and it soon became apparent that this woman's mother's name was on the ring and that the ring had been lost more than forty years ago. The date on the ring didn't match the date of the mother's wedding - but it did match the date of the engagement.

In statistician David Hand's The Improbability Principle, Hand tells the story of Anthony Hopkins and Goldie Hawn filming 1974's The Girl From Petrovka. Hopkins, keen to research the story, travelled around central London bookshops to find the book but was unable to source a copy. Having given up, he boarded a tube train at Leicester Square and on the vacant seat next to him there was a discarded book.

By now, you can assuredly guess what that book was. Hopkins told the author, George Feifer, about this story and this revealed a further twist. Feifer had let a friend borrow his annotated copy of the book and the friend had lost it in Bayswater. The copy of the book that Hopkins had found was, of course, Feifer's own annotated copy.

So what's going on? Are these stories all pure coincidence or are there darker forces at play? Chris French had another example from his own life (we all do, often many examples) that involved being a massive David Bowie fan and being particularly obsessed with the album Hunky Dory and the track Quicksand (good choice). At the same time he was reading The Morning Of The Magicians:Introduction To Fantastic Realism by Louis Pauwels and Jacques Bergier.

He wasn't familiar with Aleister Crowley or the Golden Dawn but just as the book started to touch on that subject he heard Bowie sing the immortal lines "I'm closer to the Golden Dawn, immersed in Crowley's uniform". Coincidence? Probably.

What about ten year old Laura Baxter from Staffordshire? She wrote her name and address on a helium balloon and released it. It landed in a garden more than one hundred miles away in Pewsey, Wiltshire. Found by a ten year old girl who also happened to be called Laura Baxter.

Or that's how the story goes. The story is a little different. The balloon actually landed in the garden of a farmer who knew a Laura Baxter in Pewsey and assumed it was hers so returned it. The Laura Baxter in Pewsey was nine and not ten. Sometimes the story is more interesting than the truth.

In June 1980, a lady by the name of Maureen Wilcox managed to guess all the correct numbers for both the Rhode Island and the Massachusetts lottery on the same day. Tragically for her, she chose the Rhode Island numbers for the Massachusetts lottery and vice versa. That would be very annoying.

Although perhaps not as unfortunate as Virginia park ranger Roy Sullivan who was hit by lightning at least seven times in his life (he claims more but there are seven verifiable cases). And they say lightning doesn't strike twice. The icing on the top of this coincidence cake came when Jade, my friend who I attended the talk with, revealed her own coincidence. She'd been reading about the frankly obscure Roy Sullivan earlier that very day.

Research shows people are more impressed by their own coincidences than others but I was quite impressed by Jade's. Having given lots of examples of coincidences (and there were more audience volunteered ones to come) it was time to look into a bit more logically, a tad more rationally. Starting with the law of truly of large numbers.

The odds of you winning the lottery are 1 in 45,000,000 ... but people have, and continue, to win the lottery. So that 1 in 45,000,000 chance does happen quite often which doesn't seem to make sense. But, of course, millions of people play the lottery, often every week, and often buying several tickets. Obviously that decreases the odds. Though not by enough to make it worth doing.

None of us are that good at understanding probability. Let's take what they call "the birthday problem". How many people would you need to have at a party to have a 505:50 chance of two of them sharing the same birthday (we're talking DD/MM, don't worry about the year)? Most people would say somewhere between 120 and 200 but the actual answer is 23 (with 48 people there is a 95% chance that two of them would share a birthday).

Chris ran an experiment with the audience. We were all to announce our birth date. The second person to do so had a match in the room - a room with about fifty people. After about another eight there was a second match. Probability can let you down. The odds of a perfect deal in the card game bridge are 1 in 2,230,000,000,000,000,000,000,000,000 - ludicrously high odds. Yet these deals are reported all the time.

Guinness Book of Records head honchos and right wing political activists Ross and Norris McWhirter believed the reports to be hoaxes but Professor Chris French believed it may come from people dealing 'perfectly' from new, freshly opened, packs of cards. In other words, there are often rational reasons for things that seem extraordinary to the point of being almost paranormal.

The American mathematician John Allan Paulos, in his book Innumeracy, writes about so-called precognitive dreams. The threshold is believed to be having a dream in which an event happens and then happens in real life and that event has to be something that has no more than a 1 in 10,000 chance. These things undoubtedly happen but most people, as a conservative estimate, have at least one dream they remember each night.

The odds say that each night it is unlikely you'll have a 'precognitive dream but over a year, and spread across the population of the world, 3.6% will have a dream that appears to be precognitive. Meaning 96.4% won't. Add that up over a lifetime and it's more likely you'll have at least one than not. Spread that across the entire planet and you have what looks like, but isn't, a phenomenon.

Telephone telepathy is where you can guess who is calling your phone before you've even picked up (obviously this doesn't work with mobiles) even if I thought it was, as once happened to me and my mate Shep when we were kids, when you both pick the phone up to ring each other at the same time and speak to each other before either phone even rings.

Often we'll guess who's ringing and we'll be wrong. We'll forget that. If we guess who's ringing and get it right we tend to remember it. Sometimes there are reasons we might guess and Chris gave an example. Say if you saw on the news that an ageing rock star had died. You may remember that you used to go and see that rock star with a certain friend and think about that friend. The next day that friend rings you. He or she have, very likely, seen the same story and been reminded of you for the same reason. For some reason, I thought of my mate Rob here as we tend to get in touch, more than anything these days, in these instances.

Next up it was time for a telepathy test. Chris asked us to think of a number between one and ten - but not three - and then asked those who thought of seven to put their hands up. A lot did (including Jade, I chose four, I always chose four). Then he asked us to think of an odd number (consisting of two odd numbers) between eleven and fifty. Asking those who chose thirty-seven to put their hand up, a surprisingly large number did, including Jade again. I chose thirty-five which Chris said as the second most likely option so I didn't completely outfox him during this fun experiment.

Essentially, we have a very poor appreciation of randomness. When asked to generate a string of random digits we try not to repeat ourselves but truly random number generation would involve quite a lot of repetition - because it's random.

To put an evolutionary perspective on it, our brains have evolved to keep us alive long enough to pass our genes on to the next generation and not to interrogate the truth. We mistakenly see chaos in order (a type one error) and order in chaos (a type two error) and we have two ways of thinking - intuition and reason. We need them both and we operate best when we apply both.

For long term problems we need to apply reason but for emergencies we need intuition. Imagine a sabre toothed tiger hunting one of your ancestors. Chin scratching reason would mean you end up as a tiger's lunch, the intuition to run away would save your life. Your reasonable ancestors don't exist. Your intuitive ones do.

Which is, essentially, why we struggle to understand coincidence and we ascribe it a higher meaning. It was a fascinating and fun talk and I didn't even get to mention Bertrand Russell's theory of car number plates or Daniel Kahneman in this blog. An engaging and jolly Q&A took in Einstein, pareidolia, the ancient Greeks, the bombing of Nagasaki, Douglas Adams, Elon Musk (boo). Star Trek, The Nolans, Rupert Sheldrake, the Theory of Morphic Resonance, Brian Klaas, dogs that know when their owners are coming home, constellations, and cognition deficit as a survival advantage and then there was just time for a pint of lemonade and a chat in the bar afterwards before taking the DLR back to Lewisham and the P4 bus home.

Thanks to Jade, Paula, David VB, and Andrew (former Brain of Britain champion) for joining me, thanks to Goddards for (as ever) tasty pie and mash beforehand, and thanks to Professor Chris French, the very friendly staff at The Star of Greenwich, and Greenwich Skeptics in the Pub for yet another top notch evening. That's something that is very far from coincidental.