Another convert?

Posted on March 21, 2010


My students regularly amuse me.  Recently, one girl was asking me about science and we got onto the subject of horoscopes which I was quick to dismiss as patent nonsense.  “You don’t believe in horoscopes?”  she looked surprised (she clearly doesn’t know me very well.) “No, of course not.”  “Why not?”  “Well aside from the fact that if you compare several on a single day they are very rarely the same (if not actively disagreeing with one another) they are also written to apply to almost anyone.  Have you heard of Barnum?”  She hadn’t.  “Well, he was a circus impresario.  There’s a musical about him. Called Barnum.  It starred Michael Crawford.  Anyway, Barnum’s catchphrase was ‘something for everyone’ because he believed that’s what a good circus should have.  Something for all the family and for people from all walks of life.  Well, psychologists latched on to this and christened any sentence that can apply to almost anyone a ‘Barnum statement’.  And that’s what horoscopes are made up of.  So, for example, you’ll get phrases like, ‘you are a very sociable person but sometimes you like to be alone.’  Well who doesn’t fit that sentence?  Most people are somewhere between being extroverted and introverted.  Most people are sometimes outgoing and sometimes reserved.    Or you’ll get sentences that openly flatter the reader like so,’you have a great deal of untapped creativity’  Again, who wouldn’t want to believe that about themselves?  Everyone likes to believe they have so much more to give and maybe one day, they won’t be controlled by the system any longer and that creativity will be allowed to flourish.  Maybe they’ll even become famous.  Oh, maybe one day they will tap into that well of untapped creativity.  And when you think about it, what does that even mean?  You never see horoscopes that read ‘you have real personality weaknesses and find it difficult to compensate for them.  You are undisciplined and un-self-controlled.  This means it will be very difficult for you to find a long term partner.  You will stumble from meaningless encounter to meaningless encounter while remaining ultimately unfulfilled.  Current job prospects are weak, a situation which doesn’t look like changing in the next few years.’  And why would you never read that?  Not because it is any more or less accurate than a highly positive, flattering horoscope, but simply because people would stop reading them.  People enjoy being flattered and so come back for more.  They also enjoy being told nothing is their fault.  It’s lovely to learn that all the problems you thought you had created are actually the result of a particular planet transiting across a constellation that corresponds with a star sign ascribed to the month you were born.”

The marvellous Derren Brown

A good and oft-recreated demonstration of the apparent accuracy of these generalised statements was carried out by psychologist Bertram R Forer.  So popular is this demonstration, it has found its way on to programmes by Derren Brown and Penn & Teller as well the great James Randi (all of whom you should look up and start enjoying right away if you haven’t already).  Many psychology professors use it as their first lesson for undergraduates.   Basically, a group of people is told of a new personality test.  They are asked to provide a little information about themselves, this could be a date and place of birth or the outline of their hand, something that seems personal but is in fact unimportant.  Their information is then supposedly sent away for analysis.  Upon its return a few days later, all the applicants are asked to read their results and rate them in terms of accuracy.  Usually around 80% of people say the analysis is “accurate”  or “very accurate”.  You can guess the rest, I’m sure.  Of course, everyone has been given exactly the same statement.  Many feel rather foolish for having been taken in by nothing more than clever use of language.  It is a sobering example of how gullible we can be.  And how desperate for meaning amongst the chaos.  There is a link to the full text used at the bottom of the page.  Forer took every sentence from a genuine published horoscope.  But why does it work so consistently?  I would argue it’s because we’re all human.  We all have the same worries and troubles.  Everyone (pretty much) is worried about money and love and work.  Those are the major things in one’s life so it naturally follows that they form the basis of our worries.  Really, we should see this as humbling.  We are all in the same boat.  We are not alone.  We all worry about the same things and have the same desires.  In a way, these people were seeking answers by applying for the personality test.  They thought, when they learnt it was a fake, that they hadn’t received those answers.  But maybe they did.  Maybe our common humanity is really all the explanation we need for our behaviour.

James Randi

So, back to my student.  She brought out what she believed was her trump card.  “Okay,” she said, “but I once had this horoscope that said I’d get a text message from someone beginning with a J and later on, I did.”  She then threw down the gauntlet, “how do you explain that?”  I sighed.  “Okay.  What star sign are you?”  “Taurus.”  “Right, so with 6 billion people in the world and 12 star signs to cover them all, we can assume there are around half a billion Taureans.  500 million.  So presumably, this horoscope applied to all of them as well. Do you really believe half a billion people received a text message from someone beginning with a J on that day?  What about all the Taureans in Africa with no mobile phone on which to receive a text message?  What about all the Arabian and Russian Taureans whose language doesn’t have a J in it?  The fact is, this was written with a British readership in mind.  The vast majority of Britons have a mobile phone.  And J is a very common letter for a name to begin with in Britain, encompassing as it does James, Jim, Jack, John, Joseph, Jane, Julie, Jennifer, Joan, Julia, Jemma, Jenna, Joanne, Joanna, Jackie… In short, a great many of the most popular names in the country.”

I’m not saying the writing of these horoscopes isn’t clever, because it is.  Making general statements appear specific isn’t easy.  I’m just saying there’s nothing mystical or unexplained about it.  But horoscopes also play the odds.  They work out as much as they can about their readership and then they use that knowledge to create tailored horoscopes for that readership.  I suspect that on any one day The Mirror‘s horoscope or Scorpio is different to The Telegraph’s horoscope for Scorpio.  Because they can work out a certain amount about you from the fact you bought and are reading whichever publication.  The Telegraph’s readership is likely to be older, more right wing and have a greater disposable income- because the paper is right leaning and more business oriented than the Mirror which is left wing and contains more celebrity news.  So it naturally follows that the Telegraph’s horoscope might include more about job prospects while the Mirror might play on the idea of celebrity and becoming famous.  (Stay tuned to this blog because I’m going to test these theories in a real life experiment).

All of this is not nice to think about but then, I don’t think horoscopes are very nice things.  They give people false hope and the dangerous belief that we are just puppets and our lives are controlled by outside forces which we ourselves can’t influence.  It relinquishes people of responsibility.  Oh, come on Gemma, you’re thinking, they’re just a bit of harmless fun.  And on a very low level maybe they are.  But they give way to unscientific thinking which leads people down a dangerous path.  Horoscopes give way to Chinese medicine and acupuncture and homoeopathy and talking to the dead and all manner of bullshit that gives false hope to vulnerable people while making the practitioners and peddlers of this nonsense very rich indeed.  I shudder to think of the number of deaths which can be attributed to people taking homeopathic or herbal remedies instead of the chemotherapy they desperately need because they’re afraid and in a vulnerable state and are drawn in by the spurious claims made by the alternative medicine industry (and it really is an industry). It’s deeply insidious and the quicker we rid ourselves of this anti-intellectualism the better.

Her response to this rant was rather gratifying.  “Wow,” she said, “you’ve just blown my mind.”  I would love to think that this 10 min chat sets her on a skeptical track that lasts the rest of her life.    Questioning things its good.  It’s what makes us human.  Healthy skepticism and a free mind is something to be applauded.  I practise what I preach and always tell students to confirm and verify the things I say in class for themselves.  They don’t have to believe me just because I am the teacher.  It’s okay to disagree.  As long as you can back your argument up.  As long as you can show me the evidence.  If you bring to me solid evidence of your contrary claims, I will happily change my opinion.  (And by evidence I mean actual research.  Studies.  Not a few anecdotes about how someone you knew once read a horoscope and then it came true.  Anecdotes don’t prove anything.  If a horoscope came true for you, then you happened to be the person it came true for.  Just like if you win the lottery, it’s 14 million to one against you, but you happened to be the person who won. It doesn’t mean you were destined to win.  It doesn’t have anything to do with planets millions of miles away.  Why would it?  Look at the actual research and you’ll see that horoscopes can no more predict the future than can random guessing.  Which is exactly what horoscopes are.  With a bit of clever linguistics and educated assumption thrown in.)

I will end this with a quotation from Marcus Aurelius (121-180 CE) last of the five good Roman Emperors and a Stoic philosopher, with thanks to the excellent Skeptics’ Guide to the Universe podcast for pointing me in the right direction to find it.

“If anyone can show me, and prove to me, that I am wrong in thought or deed, I will gladly change.  I seek the truth, which never yet hurt anybody.  It is only persistence in self delusion and ignorance which does harm.”


For the full text used by Forer, see this article on The Forer Effect at the Skeptic’s Dictionary

The Skeptic’s Guide to the Universe