Types of ESP

1. Extrasensory Perception (ESP) Types of ESP • ESP is knowledge gained by means other than the conventionally recognized senses • Sight, hearing, touch, taste, smell, balance, … 3 Common type of ESP that are discussed: • Telepathy • Knowing what someone is thinking • Remote Viewing • Seeing (or sensing) something that is not normally seeable • Precognition • Knowing something that is going to happen in advance

2. Why Do People Believe in ESP? Most people will cite anecdotal evidence • Coincidences: • “Last night I had a dream that I saw plane crash, and today there was a plane crash” • At one point in their life, many people have dreams like this • For some reason, this is not an uncommon dream for me • In a world of 7 billion people, it is hardly surprising if sometimes there are coincidences • Remember the hits and forgetting the misses • Of course, many times we have dreams that don’t come true • We tend to forget these • Lucky “Guesses” • Sometimes, it is not difficult to use conventional methods to anticipate results • For example, if you predict outcome of presidential races, you have 50% chance • Those who seriously research ESP don’t discount these incidents, but they don’t rely on anecdotes for evidence

3. Typical Tests of ESP • A common test of ESP uses some sort of randomly chosen object • Common to use Zener cards • Usually black and white, butI like colors • Make a big stack of them • One person concentrates on a card • Another tries to guess which card it is • Analyze data according to methods similar to what I’ve already taught you • If results are statistically better than 20%, then you have evidence of ESP • If the effect is not too small, you can measure it if you have enough trials

4. How Many Trials are Necessary? • That depends on how reliableESPis • Typical results might be 25% • If you do 1000 cards, thenthe null hypothesis says: • We would expect 200  12.7 hits • If we are getting 25% success, then we would actually get x = 250 • So the z-value would be • So if we do a bit more than1000 trials we should get pretty significant results

5. An Obvious Error to Avoid • How do we randomize the cards? • Suppose you were foolishenough to simply put five cardsin random order, and try to guess the result • Then have someone guess the cards, with immediate feedback • Because I know which cards have come up, I know notto guess that card in the future • Naïve computation says 20% chance on each, so in five cards, expect 1.00 correct out of 5 • But if you follow this procedure, you can expect 2.28 cards right out of 5 • Parapsychology researchers know this, and don’t make this obvious error

6. Results of ESP Experiments • What are the results of tests like this one? • Depends on who is doing the experiment • “Believers”, who tend to think ESP is real, usually get positive results • “Skeptics”, who think ESP isn’t real, tend to get negative results • Most experiments are done by believers • Results of believers are themselves disparate: • Some claim that everyone has a little bit of ESP, and get small effects with anyone • Others claim that some individuals are especially talented, and most people have little (if any) ESP

7. Possible Explanation of ESP Experiments • True ESP • Luck • Fraud (by the experimenter) • (Deliberate) cheating by the subject • (Unintentional) sensory leakage • Systematic errors • File drawer effect • Can luck explain it? • Some small scale experiments could be due to luck • But some large scale experiments have exhibited effects much larger than z = 5 • Unlikely that luck is the entire explanation

8. Fraud and Cheating by the Subject • In conventional science, fraud is rare, but does happen • Made up data has been published and later caught • Though this is possible in ESP research, it is probably rare • That’s just my opinion • Because of the large number of trials involved, it is necessary to compensate (pay) those who agree to have trials done • In some tests, successful psychics are rewarded (financially) when they are right • Some studies indicate that this vastly increases their fraction of “hits” • Even if you don’t have specific rewards for success, those who are unsuccessful are unlikely to be invited back (to earn more money) • There is incentive for unscrupulous subjects to cheat • Even if deliberate cheating is rare, it may be those individuals who are willing and skillful at cheating that account for the successes

9. Catching Cheaters is What Magicians Do • Most scientists are ill-equipped to catch someone cheating • Electrons don’t cheat to get more money • Strict protocols can be followed to minimize the opportunity for cheating • In some cases, ESP labs have been infiltrated by skeptics with skills as magicians to test how careful these labs are at catching cheaters • In many cases, these “plants” were able to convince the experimenters that they had psychic powers • In fact, security was often very poor • Subjects had the opportunity to “mark” the cards • Backs were visible to the subjects • The order of targets were printed out in advance with no precautions taken to keep people from peeking at them • If you really want to prevent cheating, hire a magician

10. Sensory Leakage • There are a lot of ways that you can accidentally leak information • Any deck of cards with identical backs will get random dents/scrapes/etc. over time, which allows you to identify the cards from the back • In professional gambling, decks of cards are regularly swapped out to avoid this problem • It is possible to see the reflection of cards in someone’s eyes or glasses • Though this probably only happens with deliberate cheating • Best way to avoid sensory leakage is to put people in different rooms

11. Sensory Leakage – An Anecdote • Many years ago I visited the Edgar Cayce Institute • My young daughter (5-10) and I decided to do an ESP test • The test had us facing each other, looking at front/back of a machine • On my side, one of five Zener cardsymbols would be illuminated • She saw the same five symbols, andhad to press a button to indicate whichone was illuminated • We decided to see how well we could do • I told her to watch my eyes, and pick abutton on the opposite side fromwhere I was looking • We scored over 50% success

12. Systematic Effects • There can also be subtle systematiceffects, even without cheating orsensory leakage • In one experiment, when you pressed a button, a light would indicateone of several randomly chosen cards would be chosen • The experimenter would concentrate on that card • The subject could guess the card, or could decide to pass • If they chose, it was recorded, if they passed, it was discarded • The result (success/failure) was immediately reported to the subject • The experimenter would then press the button again for the next trial • The results, after many trials, showed slightly better than chance • But statistically significant

13. So What’s Wrong With This? • Much later, when the data was examined,it was found that the same card wasalmost never chosen twice in a row • How could that happen? • It couldbe a bad randomizer, but more likely … • The experimenter pressed the button, asking for a new card to be chosen • By chance, the randomizer sometimes picks the same card • There is no obvious change, as far as the experimenter can tell • So he pressed the button again • Most people when guessing won’t guess the same card twice in a row • So the series wasn’t truly random, and the guesses weren’t truly random • If you never pick the same card twice, your odds are 25%, not 20%

14. File Drawer Effect • Not every study gets published • Suppose I’m testing ESP, and I see no effect: • Will anyone read the paper? • Will the referees think it’s worth publishing? • Some of the positive results from ESP may be due to the fact that negative results don’t get published • Of course, it can go the other way too • Referees may demand much stricter controls if you are claiming a positive effect • This is a problem with ESP, but also with medicine • Often negative results don’t get published

15. ESP In Summary • Despite many decades of study, no consistently reproducible effects have been found • The data is sometimes not statistically significant, but sometimes very statistically significant • Some of these results have been shown to have systematic errors • These errors can sometimes be very difficult to eliminate • Scientists are by and large not good at detecting deliberate fraud • In the case of extraordinary claims like this, magicians should be called in