Supernatural Science

04 November 2014

Do you believe in ghosts? For Halloween the Naked Scientists take a look at the spooky science of the supernatural. Is there evidence that paranormal beings exist and why do so many people believe in them? How do out-of-body experiences happen? What causes coincidences? Where did werewolves and vampires come from? And what tricks do magicians use to fool your senses? Join us for an eerie exploration of how the mind can create nightmarish experiences and mysterious beliefs...

In this episode

01:54 - Uncovering the paranormal

Tales from a scientist investigating haunted houses, ghostly recordings and self-proclaimed psychics...

Uncovering the paranormal
with Chris French, Goldsmiths University of London

Do you believe in the supernatural? Whether you think you've seen a ghost, or have visited a psychic who seemed to have the edge, these beliefs are far from rare. Psychic crystal ballChris French and his team at Goldsmiths University of London investigate these paranormal claims, looking at the psychology behind these beliefs. He explained how your mind can play tricks on you, with a little help from some 'ghost recordings' and an impossible musical scale.

Chris F. -   Anomalistic psychology is basically the psychology of weird stuff.  It's everything from people who think they have seen ghosts, people who think they've been abducted by aliens, people who think that they have psychic powers, and my general approach is, I'm not convinced that any of those things are really true.  So, I'm interested in the psychology behind it.  What makes people think...

Chris -   I'm disappointed now!

Chris F. -   I'm sorry.  We do actually spend quite a lot of our time also directly testing paranormal claims.  So, we'll get psychics in, say, "Do your stuff under properly controlled conditions and guess what?"  No, they're not...

Chris -   What fraction of the public claim to be psychic?

Chris F. -   It's probably not an awful lot who would actually claim to be psychic.  A sizeable minority I'd say, but in terms of how many people believe in the paranormal, then you're typically looking at; at least half the population believe in at least one or rather paranormal claim.  So, it's really interesting to us.  The question, what is it that's going on when people think they've experienced something psychic and can we explain it in kind of normal psychological terms?  I think very often, we can.

Chris -   Can we do a quick test?  Hands up here if you believe in ghosts.

Chris F. -   You're a sceptical bunch.

Chris -   Just so everyone at home knows, there's about a hundred people here and I can count about 5 hands up.  Hands up if you're a liar.  There'd be more hands going up.  So, not particularly...

Chris F. -   That's very, very atypical.  For example, on the question of ghosts, you would typically find about 40% of people would say that they believe in ghosts and of those, quite a lot of them would say they have personally experienced a ghost.

Chris -   What about if we phrase the question slightly differently?  Who here has had an experience - they can't explain that you think might have some kind of bizarre reason behind it?  So, a few more hands are going up.  Is that more reflective, Chris?

Chris F. -   Bear in mind, we are at the Cambridge Science Centre and this is probably not a typical audience.  We've got an audience of people who probably are quite into science, probably have a different attitude to lead to the general public.  So, that's not very representative at all.

Chris -   So, when you put these sorts of psychic phenomena to the test, what sorts of things do you test and how do you test them fairly?

Chris F. -   Well again, it very much depends on the specific claim.  If we test a psychic for example, the kind of thing we'd do would be - I mean, psychic explain that they can tell you all about yourself, just using their psychic powers.  They don't use any of the normal senses.  It's not just guess work.  They just use their psychic powers.  So, what we would do might be for example, to get a number of volunteers in to have a reading done by these psychics.  But we'd do it slightly differently than the way they usually operated.  We'd have the people sitting behind a screen so they couldn't see them.  We would have a situation where they don't actually ask them any questions.  There's no conversation.  They just use their psychic powers.  They write down their reading.  We'll then take those readings for say, 5, 6 volunteers, get the volunteers to come back and read through all the different readings and choose the one that was done for them.  Now, if the psychics can really do what they say they can do then there ought to be one reading there that is all about you personally -lots of personal details and guess what?  It just doesn't happen.  They actually come out, just at what you'd expect on the basis of chance, guess work.

Chris -   ...a tabloid newspaper sacked their man who did the stars and then they said, the next after they'd said they sacked him, they wrote, "He didn't see it coming."  Anyone here been to a psychic reading or anything like that?  Anyone had that experience?  Would you mind just telling us why did you go out of interest or something?  Can I just ask you?

Female -   Yeah, so I was working in Thailand at that time on malaria and it's really, really big in Thailand.  And so, it was partly to get involved with the culture and understand why people go.  There was a bit of a language barrier going on but it was an interesting experience to see why so many students and these were based in universities.  So, people would go to universities.  The students will go to where they're based and talk about it.  It was interesting to see.

Chris -   So, big cultural differences, Chris?

Chris F. -   Yeah, there'll be huge cultural differences.  But what you will find is that across any culture, any society you care to look at either historically or geographically, there will be people who claim they have these special powers, there'll be lots of people who believe that these claims are true, and there'll be lots of people who claim they have had personal experience of the paranormal.

Chris -   Anyone like to ask Chris any questions about actually how he does his research?

Sophie -   Sophie from  Blenheim . Do you think that ghosts are real?  Do you think that even if it doesn't prove that they're real, do you think they're real just because it would be cool if they're real?

Chris F. -   I think it would be cool if they're real.  Certainly, when I was your age, I was absolutely convinced that ghosts existed and I couldn't sleep without a night light.  I was terrified.  But the more psychology I learn, the more I realise that there are ways that your mind can play tricks on you.  You can think you're seeing things and hearing things that aren't really there.  You can get yourself worked up into a state.  I mean, we can actually kind of demonstrate these kinds of effects under controlled conditions where we can setup situations where people see things as like I said, that aren't actually really there.  I've actually got one kind of quite nice example of that if you let me demonstrate that to you.  This is not actually something where people are seeing things that aren't there, but one of the things that a lot of paranormal investigation groups do, when they go in with all their bits of equipment to investigate a haunted location, there's something called Electronic Voice Phenomenon or EVP.  What these people claim is that if you go into these locations which are supposed to be haunted and you have a recording device on, that if you record just all the background noise and then play it back, you can actually hear spirit voices.  Now, it's interesting that when the people who do this do it, they like to use really old bits of equipment.  They don't like modern equipment that gives you never nice, clear, crisp recordings.  They like stuff that gives you lots of background hissy noises and then when they play it back, yeah, you kind of think you can hear something going on.  Now, the explanation of what's going is that sometimes you probably are genuinely recording real people, voices.  There are really voices there.  I mean, I did a daytime TV show a couple of years back and one of these investigators was playing this EVP and it was, without a doubt, someone singing Celine Dione songs.  It was absolutely terrifying, I have to admit but I don't think it was a ghost.  If you went on to various websites, you can play this stuff.  So sometimes you can hear voices, sometimes you just get speech-like sounds.  The interesting thing is, if you go on these websites, you typically can't figure out what the message is until you read what you're supposed to be hearing and then you kind of think, "Yeah, I can kind of hear that."  So, what I'd like to do is play you some examples.  These are genuine examples of EVP and you see if you can figure out what the spirits are supposed to be saying.  I think that you'll have difficulty, but these are fairly typical kinds of recordings.  So, here we go.  Here's the first one... (recording) Anybody?  Hands up if you think you can hear it.  Somebody at the back there...

Male -   Barry.

Chris F. -   Barry, okay.  That's not too far away from what it says on the website, but it's not quite right.  I'll give it to you again.  (recording).  Anybody?  Anybody else?  Put a hand above your head now.  Somebody here...

Female -   I'm sorry.

Chris F. -   That's very good.  It's actually, "We're sorry."  I'll play it again so that you can get it.  Here we go, "We're sorry."

Recording -   "We're sorry."

Chris F. -   Maybe.  I'm going to give you one more example.  See if you know what this one says... (recording).  Any offers?  What do you think a ghost would say?  Think about the kind of thing that a ghost would say.

Male -   I think that time I heard, "I am a ghost" possibly.

Chris F. -   That's an interesting one, but I'll tell.  I mean, what would you expect a ghost to say - it's, "Come and find the cake."  Okay, so I'll play it again and this time, see if you can hear it.  It's, "Come and find the cake." (recording) Yes, it's "come and find the cake" isn't it?  Except, I played a little trick on you there because according to the website that we took that from, that's not the message.  The message is supposed to be, "Someone's in the way."  Now I must admit, to me, whenever I hear it now, I always hear, "Come and find the cake".  But I'm going to play it to you again.  See if you can hear it, "Someone's in the way" because that's how some people hear it.  (recording).  Now, it's "Come and find the cake".  It is.  I mean, what that illustrates is the way that when we've got kind of very ambiguous, very degraded stimuli, you're not quite sure what any of that is.  You can read meaning into it.  I think that explains an awful lot of the time when people think they've seen a ghost in the shadows or they think they've heard something, think they've heard a voice, etc.  there are lots of other things that can come into play as well.  Well, that's one example.

Maria -   Hello.  I'm Maria from Cambridge.  I'm just really curious.  The psychics you work with or people who think they can see or hear, when they finished working with you, does anybody ever say, "Oh my God!  Maybe I got it wrong"?

Chris F. -   You'll be amazed to know that on one occasion when we tested a psychic, we did the test, she got the results.  She said, "Well, I should have been able to pass that test.  I'm gobsmacked!"  That was her term.  "I'm gobsmacked!"  We thought, that's unusual because usually, they start making all kinds of excuses.  We always bend over backwards to make sure that they're happy with the test before we start.  No point in doing it otherwise.  We get them to sign something to say it's a fair test.  Afterwards, when they fail, they typically say, "It wasn't a fair test after all."  This woman actually, it looked like she was going to be the first one ever to say, "Well, I should've been able to do that."  Within a day or two, she changed her mind and decided it wasn't a fair test after all.

Hannah -   There's a question that's come in via Facebook. Steven Quill has been in touch saying, "What's the most spooky experience one of the panel has ever encountered?"

Chris F. -   I have spent very, very many nights in supposedly haunted houses and I must confess, it's about as exciting as watching paint dry.  I find myself sitting there thinking, "Why am I doing this?"  And then I remember - it's usually for a TV programme - so I remember, "Ahh!  It's because they're paying me."

Chris -   Ginny and Hannah.

Ginny -   So, we're going to show you that you maybe can't always trust everything that you hear.  I want everyone to listen to this and think about what you can hear, what it sounds like...(audio).  It's quite spooky, isn't it?  So, what does it sound like?  Can anyone describe it for me?

Harry -   I'm Harry.  I'm from Caldecott.  Is it someone playing the piano?

Hannah -   It might be the piano.  I don't know what instrument it is.  It could be the piano.  What does it sound like?  Is it going up or down?

Harry -   Isn't it the same few notes played over and over again?

Ginny -   What did everyone else think?  does it sound like it's staying the same?

Male -   Sounded like it was going up a scale, up a spooky scale.

Ginny -   Give us a cheer if you agree.

Audience -   Yes!

Ginny -   Did anyone think it was going down?

Audience -   No.

Ginny -   No.  So, it sounds like it's going up.  Let's have another listen.  I think it sounds a bit like someone creeping upstairs, going up and up and up.  Would you all believe me if I told you that's not actually going up and up forever?  It's all an illusion.  So, we're going to need someone to help us prove that.

Hannah -   What's your name?

Malcolm -   Malcolm.

Hannah -   Malcolm, will you come and join us on stage?  so, in front of Malcolm, we've got a big a speaker and surrounding the speaker, a little kind of almost like piano keys which - Malcolm, we're going to get you to hit each one of the piano keys, in turn, going around the speaker.

(Malcolm playing)

Hannah -   And now, Malcolm is right back at the beginning and he's continuing going around.  What's happening, Malcolm?

Malcolm -   It's just getting higher.  The notes are just getting higher.

Hannah -   Even though you're hitting same keys of the piano almost, the notes sound to you like they're getting higher.  But how can that make sense?

Malcolm -   I'm not sure.

Ginny -   A round of applause.  (applause).  So, this is a really clever illusion because it felt like you could've just kept playing them over and over again and it would've got higher and higher.  But actually, when you think about it, that ending note...wasn't actually any higher than the one we started on...  So, what's going on here is they're not actually one single note.  You've got lots of different frequencies, lots of different pitches being played together.  Each time you move one note along, each of those notes goes up a step, but the one at the very top disappears, and you add a new one below.  So, you can imagine it like a whole load of lines moving up on a page, but when they get to the top of the page, they fall off, and you add an extra one below.  So, although each individual note within that chord is going up every time you play the next one, the whole overall thing isn't getting any higher.  It's kind of like - I don't know if anyone seen the drawing of Escher's staircase?  It's this really cool illusion where it looks like you could just keep walking up and up the staircase forever but it actually goes around in a circle.  You can think of this as a kind of auditory version of that visual illusion.  But it just shows that we can't always trust our brains and we can't always trust what we think we hear.

16:06 - Out of body experiences

We examine the science behind out-of-body experiences, and even induce one in an unsuspecting audience member!

Out of body experiences
with Dr Jane Aspell, Anglia Ruskin University.

Out-of-body experiences commonly occur when people are very ill or suffer severe injuries. They are often reported as a feeling of the 'self' being outside the body, looking down on it. But what actually is an out-of-body experience, and what causes them? Out of Body ExperienceJane Aspell is a senior lecturer at Anglia Ruskin University where she investigates this phenomenon and what is going on in the brain when people experience it. She even induces these experiences in healthy people, something we thought we would like to try on an unsuspecting member of the audience, as she explained to Chris Smith...

Jane -  People commonly associate them with near death experiences.  You have the idea that somebody is - that their self or their soul is leaving their body when they're on their death bed or in a hospital bed.  But scientists have looked at many people who've had out-of-body experiences to see if there's anything that unites them, if they have anything in common.  What they found is that there's a particular part of the brain which is not working properly in people who have out-of-body experiences.  It's a part of the brain which receives information from lots of different senses, about your body, and integrates them together.  So because that part of the brain is not functioning properly, you experience yourself outside of your body.

Chris -  There's a piece of research that was published a few years ago, a researcher in Switzerland called Olaf Blanke and I was fortunate when he discovered this to be able to talk to him.  He could induce these sensations in people by deactivating a certain region in their brain and he asked them, because they were doing this in people who were having brain surgery but were awake at the time.  All of the people said that they experienced a sort of shadow person who was themselves but a little bit behind into the side of themselves.  When he gave them something to take, they would say, "they're trying to get hold of it".  They couldn't really grapple with the fact that it was them who was reaching out to take something.  They experienced this other person trying to get hold of whatever he was offering them.

Jane -  Sounds really spooky, doesn't it?  I worked in Professor Blanke's lab for 4 years before coming to Cambridge and I met a patient who'd had this experience.  It's called feeling of a presence.  It sounds really spooky.  They feel like somebody is constantly behind them and always around about 1 metre behind them and usually, they can't see them.  It's just a feeling.  So, you might have had it if you walk down a street on your own in the night and you just sort of feel that someone is behind you, even though you can't hear it or see it.  So, these patients have this feeling all of the time.  And again, it's caused by a particular part of the brain which receives information from our body.  What seems to be happening is that usually, your brain should create a model of just one of you.  But what's happening in these patients is the brain is sort of duplicating that.  So, it's as though there are two of you and that other you is experienced as this presence.

Chris -  It's quite common though isn't it, when you get people actually describing these experiences, it's a very consistent and it's a very common description that they give.

Jane -  It's very consistent, yeah.  There's always the feeling of, the self is outside of the body, which is really hard to imagine. We take it for granted that we experience our self in our bodies, usually in our heads.  It might feel like your self is sort of behind your eyes.  But in these people, the self is always outside of the body and always above the body as well.  So, there's always an experience of elevation.  So yeah, exactly, the reports are very consistent across different people which is in keeping with this idea that it's the same brain region, it's the same abnormality which causes the problem in all people.

Chris -  Haven't some researchers like you attempted to find out whether or not people really are going out of their body by hiding things in operating theatres for example, in places you could only see if you were really having an out-of-body experience and then questioning people afterwards to see if they've spotted that you'd written, "Hello.  You're a liar" on the top of the light?  So that unless they had floated up to the ceiling and were looking down then they wouldn't report the words were there.

Jane -  Yes, exactly.  I think some scientists in South Hampton are involved in this.  So, they've got some people in an accident and emergency hospital to collaborate with them and they put these cards or pictures right very high up in the room where people are having a cardiac arrest, their heart is stopping, to see if they do go up there and they're able to report back what the picture was.  They started that a few years ago.  I haven't heard of any positive reports yet.  But you never know.

Chris -  Any questions from the audience.

Catherine -  My name is Catherine from Newmarket.  You laugh about a cardiac arrest having these out-of-body experiences, but I have experience as a patient, I have many experiences as a nurse and if this room was full of nurses, 80% of them would be able to tell you a story.  But going back to the cardiac arrests, sometimes they're successful believe it or not.  The people say that they were up in a corner, looking over themselves and there's no way they could make up what we did to them.  But they will tell you in detail what has happened to them.

Jane -  I'm sure it can be difficult to explain these cases.

Catherine -  I can't explain it.  I don't know.

Jane -  I imagine they're telling you something like, "While my heart had stopped, you pressed this button on that machine and then another person came in.." or whatever.  What's happening in an out-of-body experience is your brain is receiving this information about what's going on in the world and then it's somehow reconstructing it in a way so that you experience the room from a different perspective.  So, it could be that they hear a machine being switched on, they hear somebody walking into the room, and then that is integrated into their out-of-body experience.  And that's why they say that they saw those things, but actually, it could've been that they only heard them and then they experience them as though they saw them.  That's how I would try and explain it in a scientific way.

Chris -  Chris French...

Chris F. -  There's a lot of research on out-of-body experiences and a lot of research on near death experiences.  One of the kind of question that I would always raise here is that there are some people who claim that they can have out-of-body experiences more or less at will, by doing various kinds of mental exercises, meditation, etc.  Now, that would be very, very easy to test.  Nobody is doubting the experiences.  The experience of a near death experience can be incredibly profound.  It can be life transforming.  The experience definitely happens.  The question is, what is it?  Is it really a glimpse of some kind of afterlife or is it a very, very rich and powerful hallucination.  I would say the evidence very strongly supports the latter rather than the former.

Chris -  Has anyone else got any questions or experiences?

Naomi -  Naomi from Cambridge.  I've seen two different members of my family have hallucinations.  One was visual hallucinations - my sister when she had malaria.  Another one was my daughter when she was sleep-deprived and she had auditory hallucinations.  Having seen those both, I can believe anything.  Both people were completely convinced that something was happening, but it was obvious to the rest of us that it was just a hallucination.

Chris -  Chris French...

Chris F. -  There's a strong tendency for people to react very defensively.  If you say, "Well, maybe you were hallucinating" because what they equate that with is "you're saying I'm crazy!" and that's just not true at all.  We can all hallucinate under the right conditions.  Surveys show that typically, around about 20% of the population, people who don't need any kind of psychiatric care whatsoever will report having hallucinations of various kinds.

Chris -  Well, let's see if we can demonstrate some abnormal perceptions.  Ginny and Hannah, over to you...

Hannah -  So, Ginny is just prepping up our experimental table here.  And what she's got, is a white piece of cardboard that's standing up vertically on the table.  It's going to act as a barrier.  We've also got on the table a fake hand.  Now, who can be our little volunteer for this experiment?  There's a lot of keenness.  What's your name and how old are you?

Lottie -  I'm Lottie and I'm 11.

Ginny -  What I need you to do is sit down on that stool and then we're going to put both your hands on the table for me.  Now, we're going to make sure your left hand is behind the screen so you can't see it.  In the place where it kind of should be, I'm going to put the fake hand.  Then we're going to drape this shirt over you.

Hannah -  You can't see your left hand at the moment, can you?

Lottie -  No.

Hannah -  No and what's Ginny doing to your hand at the moment?

Lottie -  She's got some wooden sticks and is running them down my fingers.

Hannah -  You're looking now at the fake hand where she's also rubbing the chopsticks across the fingers.  So, she's doing exactly, she's mirroring the action on the fake and prosthetic hand and also, the guinea pig's real hand.  How is it starting to feel because you're just staring at the prosthetic hand now?  Is it quite mesmerizing?

Lottie -  It is.  It kind of feels like the prosthetic hand is my actual hand.

Hannah -  Really?  So, it's almost like your brain is starting to represent the fake hand as your own hand.  Ginny, in that case, do we want to do something else to the fake hand rather than just tickle it gently with chopsticks?  So, Ginny is now going to get a giant hammer!  Lottie's face there was priceless.  Lottie, how did that feel?  Have you recovered?

Lottie -  No.

Hannah -  What do you think just happened?

Lottie -  I kind of snapped back into reality.

Hannah -  Did you think that your hand was being hit by a hammer at some point?

Lottie -  Yes.

Hannah -  But you now realised...

Lottie -  It wasn't.  It was the prosthetic hand.

Hannah -  A big round of applause for Lottie.


Hannah -  So, what on Earth was going on in Lottie's brain there, Ginny?

Ginny -  Our brains have to work out all the time, what is our body and what is not our body, what's the microphone you're holding, and all of that sort of thing.  What it does to do that is it combines different information it's getting from its senses.  So, most of the time, we can see our hands and we can also feel them.  So, if you see something being prodded and feel roughly the same thing, it's a pretty good guess that that's your hand that's being prodded.  So, what we were doing here is we were really confusing Lottie's brain by having her get the same feelings as what she could see happening on a hand that wasn't really hers.  That was tricking her brain.  It was making her brain think that that rubber hand was probably her hand because she could feel what was happening to it or at least that's what it seemed.  So then when I got out my large, heavy metal hammer, and thumped it down on this hand that she'd started having the feeling that it belonged to her, of course, poor Lottie jumped back, thinking I was about to hit her with a hammer.  I wasn't and it didn't hurt at all, did it?

Lottie -  Nope.

Ginny -  No.  So, it didn't actually hurt her but it gives you that moment of panic that something big and heavy is coming towards your body and it feels like it was her body even though it actually wasn't.  Jane, is that something similar that you do to induce these experiences in people?

Jane -  Yes.  So instead of having just a hand, what you could do is have a whole mannequin ,because you want people to experience that their self is somewhat different to their body.  So, the experiences I generate are not as strong as an out-of-body experience.  But usually, I would have somebody standing in a room.  They'd be wearing sort of virtual reality goggles like Oculus Rift or something.  A video camera would film them from behind.  The virtual reality goggles are connected to the video camera so then they suddenly see their double standing in front of them which is quite spooky.  Somebody has a long stick like you were using on the hand and then you tap the person's back with the stick so they can feel the tapping on their back and see the tapping on their double in front of them.  People start to experience then, that their body is actually over there where the virtual body is and that their self is outside of their physical body.  So, that's how I try and create out-of-body experiences in healthy people.  It's a little bit similar but it does...

Chris -  Did you hit them with a hammer?

Jane -  What some other researcher does is get a knife and it looks as though they're stabbing it and they also get a big fright like Lottie did.

Chris -  So, what do you learn by doing this?  It is exciting.  I have done that and it really is very strange to experience when you feel you're not in your own body, but why is this important, us understanding this?

Jane -  It's interesting to understand how an out-of-body experience works to start with, but my research in general is looking at how the brain creates a sense of self.  How on Earth does it generate a feeling of who you are, all these things that we take for granted that our self seems to be inside our body, inside our head, that we know this body is ours, we don't experience somebody else's body as ours?  So, how does a brain create this thing which is the most important thing in the world to us, our self?  So, it relates to that really and it's only by manipulating your sense of self in these kinds of experiments that you can try and work out how the brain creates the normal sense of self that we sort of take for granted.

Chris -  From Anglia Ruskin University, ladies and gentlemen, thank you, Jane Aspell.

30:12 - The maths of coincidence

David Spiegelhalter discusses why seemingly unlikely events occur all the time- although not often to him!

The maths of coincidence
with David Spiegelhalter, University of Cambridge

Have you ever thought about an old friend, only to have them call that same day? What about singing a song just before it comes on the radio? These spooky coincidences are surprisingly common when you look for them, but can be explained by simply psychology and maths, according to David Speigelhalter of Cambridge University. He explained to Chris Smith and the live audience why creepy coincidences aren't as creepy as we might think...

David -  I'm interested in strange things that happen to people, that people say, "Whoa!  Fancy that!" and remember some of these things - the stories I've got.  People will remember for the rest of their lives some of the strange things that happen.

Chris -  Well, like what?

David -  We collect them.  We've got a website at Cambridge Coincidences and we've got thousands of them.  Some of the most popular ones, and you could tell how old some of these are, how long they've remembered them, because they're about public telephone boxes.  I think we got four now where someone's walking on the street, an old red public telephone box, it rings as they're going past it,  "Oh!  I might as well answer it."  They answer it and it's for them.  Well, I wonder if anything strange has happened tonight.  I mean, there's about 70 people in the audience.  I've actually asked you to write down your birthdays so I've got them.  Now I wonder, would it be strange if two people in the room had the same birthday?  Is that strange?

Chris -  Hands up - this audience if you would be surprised if someone in this room had the same birthday as you.  This is a sceptical audience.  So, about 5 or 6.

David -  What happens if two people in the room walked in with the same birthday and happen to sit very close to each other?  Would that be quite cool?  Come on you miserable lot, that would be cool!.  Okay, stand up if you were born on the 27th of March.  Quite a long way.

Chris -  So, we have one lady and one man and they're on the opposite side of the auditorium.

David -  Yes, sit down.  Okay, stand up if you were born on the 6th of February.  Opposite sides of the room.  This is terrible.

Chris -  It's a good hit rate so far.

David -  Yeah.  Stand up if you're born on October the 6th.  Not bad, but 6 or 7 feet away from each other.  That's not bad.

Chris -  We should point out, each time we're getting about two people standing up.  Each time, you've had a pair of people sharing those birthdates.

David -  Yeah, I'm not choosing these dates at random.  So, the sort of stories some people report to us, the classic coincidence.  I don't know anyone has had this when they meet a stranger and suddenly they find this connection with the stranger.  They went to the same school.  They know somebody in common is a usual thing.  I was just looking through the ones people have sent in just in the last week, somebody meeting somebody and finding out that they lived in the same house.  The other one is finding a connection with the one you know and then again, finding this very strange connection.  We've had one, a beautiful one, a married couple who discovered they were both born in the same bed.  They got married, yeah.  They found they were both born in the same little village in Germany which only got one little hospital and one little bed where all the babies were born.  Another one, people have just sent in a married couple who discovered that they'd both been in a hospital as children at both exactly the same time.  There's these wonderful strange ones where there's a picture of the husband when he's a boy sitting on the beach and there's his wife, just walking along behind on the beach.

Chris -  But isn't the whole point of every single one of these examples is notable because it's exceptional, whereas all of the other benign things that happen in people's lives that don't have these bizarre coincidences attached to them, people just ignore?

David -  Exactly.  There's so many million things that happen to us all the time.  There's inevitably going to be some strange things that happen.  For example, who's born on the 2nd of September?  Not bad, about 6 feet, okay.  How about on 10th of January?  Miles away, that's useless.  You all deliberately sort of - there's this powerful force.  It's making people sit at opposite ends of the room if  they've got the same birthday.  But cool, there's a lot of people in here with the same birthday.

Chris -  David, isn't it a coincidence that none of the people with the same birthday are sitting together?

David -  Wait, I haven't finished yet.  We'll see.  The other ones I love are where people rediscover objects.  It was lovely, someone sent one in recently where they had carefully stencilled on a lovely picture on their chest of drawers.  And then they've given it to a friend and the friend had gone away a couple of hundred miles, and years later, this woman had moved to this new town and she got a friend next door who invited her into her room and there was the chest of drawers - complete stranger, at that.  So, when these things happen to people, they go, "Whoa!  That's really cool."  People in the past have invented theories why these things happen.  A guy called Kammerer had this theory of seriality.  It was a sort force that caused these strange things to happen more than they should and Jung had this idea of synchronicity.  This is definitely to do with premonitions as well that we could feel things happening before they did.  We banned premonitions from our website.  I don't let them go in there.  I'd only accept premonitions if people told me them before the event happened.  Afterwards, it's cheating.  Okay, 7th of March.  They're not sitting next to each other.  Pretty good, but not quite there.  We'll see.  So yeah, those are sort of things, and then there's numbers.  There's people, the pin number keeps on cropping up, same pin numbers, someone wrote in and said, "There's the same pin number from my child's primary school and the bike lock at work."  But these things happen.  The other thing is, we get a lot of people writing to us saying, "These things keep on happening to me.  It's really actually quite disturbing.  These things happen to me all the time.  I keep noticing these connections between everything."  I'm afraid - I do believe they do happen to some people more than others.  I really do.  They never happen to me.  Coincidences never happen to me.  I once had someone phone me up when I was on the train about a story about a bacon sandwich while I was eating a bacon sandwich.  But that's the only time that's happened to me.  It was so obvious, I couldn't miss it.  Now the point is, now why don't they happen to me?  I'm the sort of person who goes around, staring at the ground.  I never notice what's going on around me and I never speak to anybody at all.  I'm miserable.  I could sit next to someone in the train for hundreds of miles and not utter a word.  So, these things never happen to me.  But if you're the sort of person who sits next to someone in the train and starts talking to them, or you're the sort of person who actually notices what's going on around you, and then notices, "I saw that person earlier in the day," then that's who they happen to.  The coincidences happen. So we have people, they happen to them all the time because they notice things and they talk to people.  I could sit next to my long lost twin I was separated from at birth and I would never know because I'd just get up without speaking to them.  So, who knows how many things I've not noticed?  So, what I'm amazed at is not how many coincidences there are but how few there are.  I'm afraid I failed rather on the sitting next to each other.  Got quite close, but there were 6 pairs or 7 pairs of people that shared birthdays in this room, which I think is quite a good coincidence.

Chris -  Any questions for David on the science and study of coincidence?

Anne -  Anne from Canada.  I'm just wondering how you go about saying this.  Are you using numbers and statistics and probability to study how coincidence happen or...?

David -  Yeah, I'm a statistician.  I work in the math department here.  So, where possible, we try to do the maths.  So, the people sharing birthdays, I can work out exactly what the chances of various pairings in this thing is.  I know that if there's 23 people in a room, there's a 51% chance to them sharing the same birthday and so on, and so on.  So, I can do all these calculations and sometimes on the pin codes, you can do the maths.  Does anyone share birthday with their parent, same birthday as their mom and dad or anything like that?

Anne -  Anyone got a birthday this year?

David -  Anyone got a birthday shared with a brother or sister?  Who isn't a twin.  I don't care.  That doesn't count.  That's cheating.  Because we've got I think 5 examples of people with us, 3 siblings, all with the same day, but born in different years.  So, they were all born on each other's birthday.  The chance of that happening, we know is 135,000 to 1, which is rare.  It's extremely unusual for it to happen, except that it happens every year in this country because there's 160,000 third children born every year in this country.  And just by chance, there'll be one - you can expect one to match, have an older brother and sister born on the same day as well.  So, they come up in the news.  If you Google '3 births in the same day' they'll come up all time and the Daily Mail always gets the odds wrong.  It says it's 48 million to 1, which it isn't.

Chris -  Ladies and gentlemen, David Spiegelhalter.


(Callum) -  Callum from (Stratum).  Are you destined for each coincidence?  So, if you keep crossing paths with someone else, is it destined for you to always meet with them or mix with them?

David -  Whoah!  That's a big question.  That's quite a tricky one really, because you're really talking about almost predestination, is everything we do actually sort of pre-decided and we don't have to choose ourselves, there's no randomness and no freewill, which is a reasonable argument that some people have got.  The fact that we don't know what's going to happen it's just because we don't know, it is pre-decided, we just don't know what it is.  I don't have a too strong opinion on that at all.  What I say is that the fact that we don't know means that it might as well be random because we don't know, and we don't want to know.  Who would like to know what they're going to get for Christmas?  Yes.  All the kids want to know what they're going to get for Christmas.  Come on.  Live with uncertainty.  But the grownups don't, no, look at this.  Adults are quite happy about it.  Let's say, if I were a great all powerful being that could tell the future and I could tell you how long you're going to live.  Who would like to know?  Yes, look at these kids.  They want to know.  Why do you want to know?  I would say, the young people are the ones who want to know.  Why do you want to know?

Sophie -  Sophie from Blenheim.  I want to know because then if you're going to live a really long life then you could plan it.  But then if you weren't, then you could think, well, what's the most important thing I need to get done in my life and do that first.

Chris - Run up a big bill on the credit card.

David -  Exactly, well done.  If you knew you could plan it - so, that's a very sensible thing to do but most people - notice that as you get older, you're actually prepared to embrace a little bit more uncertainty in life and you quite like it.  So, I think that's a really interesting age profile in that.  But unfortunately, I'm not an all-powerful, all-knowing being, so I can't tell you.

41:27 - The psychology of magic

Magic tricks amaze and intrigue us, but the psychology behind these illusions is just as fascinating...

The psychology of magic
with Gustav Kuhn, Goldsmiths University of London

Magic shows are hugely popular, but just how do magicians make us fall for tricks, over and over again? Gustav Kuhn, from Goldsmiths University of London, is a psychologist working on attention, and also a magician. He showed Chris Smith, Magician Ginny Smith and the live audiences the secrets behind a couple of his tricks, and explain what they can tell us about how the brain works. 

Gustav -  I started off as a magician and my interest in magic really led me to study psychology and now, I study the science of magic.

Ginny -  If we look at science, are we going to ruin the fun of magic?

Gustav -  Well, I don't think so.  I mean, magic is very interesting in that magicians have developed really very powerful techniques to manipulate your perception.  By studying some of these techniques, we can actually work out quite a lot about how the brain works.

Ginny -  Can you show us a trick then?

Gustav -  Yeah.  I will show you a couple of tricks.

Ginny -  Okay, so I'm going to try and describe what you're doing for our radio audience.  So, you've got a Ping-Pong ball and you're throwing it up and down in one hand and it's gone.  You threw it up and I saw you catch it again, then you threw it again and I saw you catch it again then you threw it again and it disappeared.

Gustav -  So, this is known as the vanishing ball illusion.  It's actually is very, very simple.  How many of you saw a ball move up in the last throw?

Ginny -  That's at least a third of the audience think they saw it going up.

Gustav -  So about a third of the audience.  So, what's happening here is I've got a ball and I throw it up in the air a couple of times and on the final throw, I just pretend to throw it up, but in fact, it's actually held inside my hand.  Now, what's very interesting about this illusion is that most people actually experience a ball moving up and then disappearing somewhere sort of like between me and the ceiling even though the ball hasn't actually left my hand.

Ginny -  We're getting lots of nods from the audience, people who definitely thought they'd seen that ball.

Gustav -  And so, this is a really nice example to demonstrate that really what you're seeing is not necessarily the way the world is, but it's much more related to the way that you expect the world to be.  So because you're expecting the ball to be kind of like leaving the hand, that's why you actually experience the ball sort of like moving up.

Ginny -  And it is what you were doing with your hand and the fact that you actually followed it with your eyes, is that important as well?

Gustav -  Yes, so in magic, social cues are very important, so where I'm looking.  So, if I do the same illusion again, but this time, I'm just looking at the hand that's holding the ball, well the effectiveness of the illusion is really reduced.  What this shows us is that our brain is automatically picking up cues to predict what the world is going to be like in the future.  I can show you another example that sort of like highlights the importance of these social cues as well.

Ginny -  Who wants to see another trick?

Audience -  Me!

Ginny -  I think they'd like to see another one.

Gustav -  So, this is again is a very simple trick.  I've got a green lighter here on the table.

Ginny -  There's a green lighter on the table.  You're lighting it and clicked your fingers...oh, it's gone.  So, it was in your left hand.  You lit it.  You waved your right hand over the top of it then you opened your right hand.  It definitely wasn't in your right hand.  But then you also opened your left hand and it wasn't in that hand either.  Is that what everyone else saw?

Gustav -  So, can we just have a show of hands of how many of you saw how the lighter disappeared?

Ginny -  We've got a few hands.  What did you think?

Male -  I saw him dropping it.

Chris -  Gustav, you've been caught out.  You dropped it apparently.

Gustav -  I'll do exactly the same thing again.

Ginny -  Right.  So, you've lit the lighter, you waved your right hand and clicked, you've - oh, it's on your lap!

Gustav -  Now, how many of you saw how the lighter disappeared?

Ginny -  Okay, most of you saw it that time.

Gustav -  Yes, so the lighter was really just dropped.  This is not actually a real magic trick.  I'm kind of using misdirection to sort of demonstrate really how little of the environment that you're normally aware of.  So, what's happening is I'm picking up the lighter, I light it so we got a bright flame, and this flame will actually capture your attention.  I then pretend to take the flame with my hand and I'm using my social cues.  So, I'm using my gaze to distract your attention and move your attention from the lighter to my other hand.

Ginny -  So, we're all watching your right hand which you've been waving around over the flame and you've brought away from it.  So, we stopped looking at your left hand, the one that had the lighter in.

Gustav -  Yes.  So, no one's attending to the left hand holding the lighter.  I'm looking at the other hand, I'm snapping my fingers so you can hear a sound.  I'm moving it, hopefully, misdirecting your attention and therefore, preventing you from seeing the lighter drop.  One of the remarkable things about visual perception is that I'm kind of looking out here in this audience and I feel like I'm aware of most of the things that are actually going on around me.  Yet in actual fact, once we start probing our visual awareness, we realise that you're actually only aware of a really very small fraction of the information.  So, although you think you'd see things, in actual fact, most of the time, unless you're actually attending to them, you don't necessarily see them.  In a lot of our research, we use eye tracking that allows us to measure exactly where people are looking.  What's really remarkable there is that people can actually be looking at the lighter and yet, they still don't see it.  And of course, intuitively, you think that surely, if I'm looking at something, I should be able to see it.  But what a lot of these research is really telling us is that if your attention is being distracted, you just won't see it even if it's really right in front of your eyes.

46:53 - Where did werewolves come from?

Deborah Hyde examines our fascination with vampires and werewolves, and where the ideas came from...

Where did werewolves come from?
with Deborah Hyde

Debra Hyde is the editor of Skeptic Magazine, and an expert in the history of folklaw. She is particularly interested in 'supernatural predators', like vampires and werewolves, which crop up in stories from a variety of cultures, as she outlined to Chris Wolf HowlingSmith...

Debra -  Scepticism includes a lot of areas.  It can include cryptozoology for example - people who believe they've seen something like the beast of Bodmin Moor or Big Foot. Perhaps people who feel that they've been abducted by aliens or even fairies as would've been more fashionable a hundred years ago.  We're interested in an evidence base for things.  We're interested rather than in our perceptions which I think we've seen this evening can be so frequently faulty.  We're interested in the evidence to see what's real and what isn't.

Chris -  What about these consistent stories of Beasts of Bodmin and vampires and all that kind of thing?  Where do they come from?

Debra -  Vampires were probably a misunderstanding of normal processes of decomposition.  They just happened at a specific time in history.  It was a couple of centuries ago really and the reason that the stories came out when they did was political.

Chris -  What is a misunderstanding of the process of decomposition?

Debra -  Our ancestors, for very, very good reason didn't understand decomposition the way we do.  We can study these things scientifically and safely, but years ago, you wouldn't keep corpses around for the very good reason that they were a hygiene problem.  So, for example, when a body goes into rigor mortis, as is perfectly normal, leaving it out for a little while, you would realise that actually, the flexibility comes back.  So, if people saw a body that had regained its flexibility, they might think that it was actually still quite life-like, that it hadn't passed over to the other side.  What if it had failed to decay?  What if you didn't have bones in a coffin anymore?  What if you actually had flesh?  And if you've got somebody buried in winter for example, the ground is very hard and it's very cold.  You can in effect, put people in a freezer for 6 months.  It's not necessarily that unusual that they wouldn't be a skeleton yet.  But it would be quite unusual and quite scary for people who didn't understand this, that there were other variables at work.

Chris -  But where did this whole idea of this fetish for sinking your teeth into someone's neck come from?

Debra -  That was much later and we understand it, we understand that if a creature has its blood taken out, that it dies.  It was thought that there was a life force attached to it.  Literally, the blood being taken out is a bit more of a literary trope that comes later with all of the romantic literature.

Chris -  What about werewolves?  I've seen the Were-rabbit - Wallace and Gromit.  That's really good but what about the werewolf?

Debra -  Well, that's a really interesting thing that you should mention a were-rabbit because when I do a slideshow, I show a list of all of the animals that can potentially turn into were-animals in folklore, commonly throughout the world.  I have creatures like hyenas and tigers, and cats and jackals.  Is there anything that you can think that actually unites those types of creatures?  What's a similar theme?

Freddie -  Freddie from Little Downham.  They're all four-legged and they're all sort of, in the same, sort of , cat family, with maybe few exceptions.

Debra -  There are cats.  They're definitely a lot of cats.  Are there any other similarities between those kinds of things, the habits of those creatures, the kinds of things they do?

Charlie -  Charlie.  I'm from Caldecott.  They all have big teeth, sharp teeth.

Debra -  They do.  They have big teeth and big teeth are for hunting.  That's the thing about all of these creatures is they're apex predators.  They're incredibly powerful. And it seems that if people want in their minds to think of somebody turning into an animal that nobody would take that great power and turn into a were-hamster.

Chris -  What is the sort of modern day equivalent because obviously, those things came along because obviously, those things came along because people were troubled by not actually understanding the basis of the science that was going on?  Have people now reinvented new threats and new sorts of equivalents based on their more modern understanding of the world around them?  Has the interpretation moved on?

Debra -  I think it would be a mistake to assume that just because we live in a technologically based society that people still don't have these kinds of beliefs.  There are very prevalent New Age beliefs, people who believe in angels and things like that.  The thing that's interesting to notice, if you go into history, that so many of these creatures are very dangerous and they're quite random.  And so was life.  An awful lot of people died prematurely in historical times.  It's very easy for us to forget the effect that antibiotics and vaccinations, and safe midwifery processes have had, that it's had on human death rates.  In medieval times, there was about a 1 in 10 chance that you would die giving birth.  It's very, very unusual now.  These days, if you talk to people about supernatural creatures, they're quite often likely to believe in lovely things that help them out because our lives are benign and safer.

Chris -  Any questions?  Georgia...

Georgia -  Do you think these beliefs are good for people to have or do you think they're more damaging?

Debra -  It varies.  It's very noticeable in history that when there are random environmental factors, when there are wars, when there are epidemics, when there is mad inflation or something like that, that people get very panicky and they're likely to scapegoat other people.  It seems to be tremendously satisfying for groups of people to look to blame one person and then to perform a ritual to get rid of that person or to get rid of that effect that's happening.  Now, it doesn't actually work, but it makes people feel better temporarily.  You can see that with witch hunts and things like that.  So, sometimes it's not particularly nice, but it makes people feel temporarily better even though they can be wrong and they can do very terrible things.  In some ways, I think that belief in the supernatural has been very useful for hygiene type purposes - keeping corpses separate from people.  We don't bury the dead under the house.  With a few exceptions, we bury them in graveyards and things like that.  So, the sense of contagion that we have which can feed into supernatural constructs is also actually very good at avoiding disease.

Chris -  Ginny and Hannah...

Hannah -  Can we have a final volunteer to help us make some ectoplasm?

Callum -  I'm Callum from Streatham.

Hannah -  Wonderful!  Thank you very much for joining us on the stage, Callum.  Ginny, you've got here a lovely perspex bowl which is nice and clean for the moment and you've also got some PVA glue, so the kind of glue that you get in your school art class.

Ginny -  Okay, so Callum, what I need you to do is just put a little blob of that in the bottom of the bowl.  So, this is just standard PVA glue.  Just tip some into there.  Yeah, that will do.  Stop there.

Hannah -  So, that's probably about half a tablespoon, would you say, Callum?

Callum -  I would say that.

Ginny -  Good.  Now, just because it's a bit more fun, we've got some green food colouring.  Do you want to tip just a little drop in there and give it a stir around?

Hannah -  Callum, what's it looking like now?

Callum -  It's looking like snot.

Ginny -  It's a nice bright green colour isn't it?  I'm just going to add a little dash of water. And can you stir that in for me?  Have a feel of the kind of texture of it.  What does it feel like?

Callum -  It's quite runny, but still quite thin.

Ginny -  Yeah, sort of gluey but quite runny glue because we've stirred in a load of water.

Hannah -  It's kind of dripping off your fingers there wasn't it Callum?

Callum -  Yeah.

Ginny -  So now, what I have here is spray starch.  Have you ever seen this before?

Callum -  No.

Ginny -  Do I take it you don't do a lot of ironing at home?

Callum -  That is correct.

Ginny -  Those of you who do do ironing may have seen this before. You spray it on your shirts and then you iron them and then it makes it nice and crisp, and fresh.  So, it's just the sort of stuff you might find in laundry cupboard at home.  I'm going to spray some in the bowl and I need you to stir it in for me.

Hannah -  So, what's happening as we're stirring in the starch?

Callum -  It's starting to thicken the liquid.

Ginny -  I'm going to put a bit more in, give that a good stir...

Callum -  It's starting to thicken even more.

Ginny -  Can we see it's almost going kind of stringy as I pick it up?  Let's put some more in,  keep going.

Hannah -  Wow!  That's transforming before our very eyes.  Callum, what's happening there?

Callum -  It's starting to combine together and become stronger and harder.

Ginny -  So now it's started sort of pulling away from the side of the bowl, hasn't it?  We've got a big oozy lump.  Do you want to get your hands in there now?

Callum -  Yes.

Hannah -  It's now coating Callum's hands and just stringing down.  Callum, how does that feel?

Callum -  Quite cold!  Quite soapy.

Ginny -  Sort of slimy, isn't it?  But look, if you pick it up really, really quickly and sort of roll it around between your hands, you can actually almost get it to form a sort of ball and then as soon as I let go, it goes back to being liquid.  Can you see that?  Okay, let's try adding a bit more.

Callum -  It's kind of jelly-like.

Ginny -  So, the more starch we've added, the more solid it's become and it's gone from being entirely liquid to being this kind of stringy gloop that you can actually sort of roll around in your hands.  It's almost like flubber.  If we kept spraying the starch in, it would get firmer and firmer, and firmer as you go.  If you try this at home, you can experiment with adding different amounts of starch to make a firmer or a wetter slime.

Hannah -  Callum, can you come up with some idea for why you think this might be happening?  Why do you think adding starch to glue might make it more solid and slimy-like?

Callum -  Is it something to do with the chemical reaction that is taking place?

Hannah -  Ginny!

Ginny -  Very good answer!  What you have is PVA glue.  It's a long chain molecule.  So, if you imagine every row in this room, if you held hands with the people next to you then each of you would be a polymer, long chain molecule like PVA.  What's happening when we're adding starch is that it's joining those molecules up.  So, then if you imagine, you're still holding hands with the people next to you, but if a few of you reach back and grab the hand of the person behind you so that all the lines are joined up - now originally, when you were just holding the hands of people next to you, if I'd ask you to move, you could quite easily have moved - one row could've gone left and the next row could've gone right.  That's why the PVA can move around.  The molecules can slide over each other.  When we add the starch and it causes those molecules to join up like when you joined hands with the person in front or behind you, the molecules can't slide over each other as easily.  They're what we call cross-linked and that makes this harder, stretchier material.  Now, they can still slide a bit because they haven't cross-linked all that much.  But the more starch we add, the harder it'll get for them to move around because the more of you would be holding hands with the people in front of you.  That makes a harder, firmer, mixture.  That's actually the same thing they do to rubber.  To make the rubber for your tires and things, they add sulphur and that crosslinks the rubber molecules, making it firmer so you get nice hard bouncy tires.  You wouldn't want tires that were made out of something like this slime.

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