Posted
on September 29, 2016
“J.B.
Rhine Is an Ass.”
That
was the name of a newspaper article published by famous Sherlock Holmes
author, Arthur Conan Doyle, about today's birthday boy, Joseph Banks
Rhine.
Why
did Doyle think so poorly of Rhine?
Sir
Arthur Conan Doyle was great at creating a complex fictional
detective character who remains popular to this day. Doyle was really
good at crafting detective stories that have kept generations of readers
interested. But he wasn't really good at everything.
One
of the big not-so-good things about Doyle was his uncritical attitude
about spiritualism, communicating with the death, mediums and seances
and all the rest of it. Doyle was very enthusiastic about all of that
stuff. So enthusiastic that he became a True Believer, and he wasn't
able to think clearly about the topic. If people said that a
particular séance was full of trickery, Doyle pushed away the
evidence. If someone said that a particular medium was a fraud, Doyle
ignored the report.
J.B. Rhine had attended a séance put on by
medium Mina Crandon. He claimed that he observed Crandon kicking a
megaphone to give the impression it was levitating (rising up through
the power of an invisible spirit), using luminous objects to represent otherworldly spirits, and doing other tricks. Rhine wrote
an article exposing Crandon's tricks, and Doyle attacked him in response.
The
weird thing is that Rhine was a bit of a believer, too. At least he wanted to be.
Rhine had
studied to be a scientist – a plant scientist, or botanist, to be
exact. While at the university where he was earning his Master's and
PhD, Rhine heard a lecture given by none other than Arthur Conan
Doyle. In the lecture, Doyle said that there was scientific proof
that mediums really were communicating with the dead. (That's
incorrect, by the way.) And the idea fascinated Rhine and his wife so
much that Rhine soon left botany for a new “science,”
parapsychology.
Rhine
is pretty famous for his research on ESP, or extra-sensory
perception. Could people know what is on a hidden card, or what
another person is thinking, or what is going to happen soon –
through some previously unknown ability?
With
his scientific training, Rhine knew that he should set up a properly
controlled experiment with which he could test these possible powers
of the mind. And, from what I can tell by reading about Rhine and his
work, I think he tried to set up a proper experiment. I think that he
didn't want to fool himself like he probably realized Doyle was
fooling himself about mediums and seances.
But
he did fool himself, unfortunately.
Working
at Duke University, NC, Rhine tested Duke undergraduate students for
ESP using Zener cards. The experimenter picks up a card in a shuffled
deck of 25 cards, observes which of the five symbols is on the card,
and records the guess of the student being tested.
Most
students guessed right about as many times as chance predicts –
about 20% of the time. But some students did way better.
At
times, at least.
Rhine
thought that his amazing undergrads had ESP (and I do think that he
was fooling himself, not trying to trick people), but here are some
of the problems with this experiment:
- Some people are really good at making predictions because they have excellent memories about which cards have already been played. There are five cards with each symbol, and the experimenter just went straight through the shuffled deck; certainly later “guesses” had a much better chance of being correct for test-takers with good memories.
- Studies have shown that poor shuffling techniques make it much easier to predict cards, and Rhine's first experiments were done with experimenters shuffling cards by hand.
- Another way of making a correct prediction is to note slight stains and smudges and bends and other imperfections in the cards. Some of the undergrads used the cards multiple times for identical tests; it's possible that they got to know (consciously or unconsciously) the back-sides of the cards. In the earliest tests, it was actually possible to see through the cards in some lighting conditions!
- It's possible that the experimenter who observed the cards had a “tell” – some difference in how he held or looked at the cards, how he sounded, depending on the card. Much more likely is that test takers might have been able to see at least a bit of the cards reflected in the experimenters' glasses or even their corneas. Note that each of the symbols is a different color.
- Some of the “exceptional subjects” – the undergrads who seemed to guess the cards at a better-than-chance rate – were actually allowed to handle the cards, shuffle and cut the cards, themselves. We've all seen magicians who are able to manipulate decks of cards in what seem like remarkable ways – so any handling by those taking the tests throws the data from the tests into question.
- Chance evens out to 20% – but only after a LOT of random trials. Certainly there can be what seems to be remarkable runs of luck, of particular dice throws, say, or high-scoring poker hands – but if you keep throwing dice or dealing poker hands, you will eventually see the magical-seeming run flattening out.
Rhine's “exceptional” under-grads sometimes seemed to guess better-than-chance, sometimes seemed to guess worse-than-chance, and of course sometimes seemed to guess at the chance rate of 20%. Unfortunately, investigation of Rhine's work showed that he tended to think that the positive results showed ESP, and that the negative or neutral results could be explained by the subject being tired or bored or even angry.
As
others studied Rhine's results and complained about things like
reflections, see-through cards, or other ways in which test takers
could improve their guesses, Rhine kept trying to devise better
experiments that wouldn't allow “sensory leakage” or cheating.
But then he was unable to find any high-scoring subjects.
After
the eventual lack of success using the Zener cards, parapsychologists
no longer use card-guessing studies.
Like
I said before, I think that Rhine meant well, and his work with
medium Crandon demonstrates his lack of desire to willfully cheat in
order to believe in amazing ideas. However, I think he let down his
own scientific training in the way he reported his results. He didn't
design his experiments well, nor did he describe his experimental
methods with enough clarity, he used math in a fudgy way instead of
as a tool to make the testing more rigorous, and worst of all, he was
selective in his reporting with the result that he exaggerated his
successes and explained away his failures.
Physicist
Richard Feynman once warned:
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