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Live ESP Experiment: Sexual Arousal Going Backwards in Time (parapsych.me)
44 points by parapsych on Jan 7, 2011 | hide | past | favorite | 51 comments



Re "this only works for straight males" - the research that I have read indicates that females are aroused by a much broader range of visual images (even images of monkeys), whereas males are focused on the images which are in their sexual preference realm. [I believe I read this in "Sex Before Dawn", a book I quite enjoyed.]

So, anyway, it might work for females too.

I was going to try it out, but after the first picture, I realized I should probably wait until I get home. :)


the research that I have read indicates that females are aroused by a much broader range of visual images (even images of monkeys)

Physically aroused, not psychologically. There is no way to say this delicately but the women in the study would start lubricating when witnessing anything sexual in nature but they weren't on the verge of orgasm or anything. They could still find the imagery unpleasant and in fact didn't actually feel aroused while witnessing the monkey business. The researchers hypothesized that this had to do with protecting the lady parts even in a situation of unwanted sex.


Good point, thanks for making that distinction.

I think I would still reword "this will only work for straight males" to "this will only work for those that are aroused by men doing women" (or whatever the subject matter is, in this case). The audience is probably bigger than originally presumed.


I feel like the fact that I can choose how many times to play might throw things? If I were more likely to stop after non-arousing image than after an arousing one, what will that do statistically?


Even if you decide to stop having kids after your first son, the population of males / females should be split evenly, so I don't think it would make a difference.


I don't think that's true.

  public class test {
      public static void main( String[] args ) throws Exception {
          int boys = 0, girls = 0;
          for (int i = 0; i < 1000000; i++) {
              boolean isBoy = (Math.random() >= 0.5);
              while (! isBoy) {
                  girls++;
                  isBoy = (Math.random() >= 0.5);
              }
              boys++;
          }
          System.out.println( "Boys: " + boys + "\nGirls: " + girls );
      }
  }


I don't know what output you're getting, but this is what I got:

  $ java test
  Boys: 1000000
  Girls: 996931
  $ java test
  Boys: 1000000
  Girls: 1001605
  $ java test
  Boys: 1000000
  Girls: 1001656
  $ java test
  Boys: 1000000
  Girls: 999473
  $ java test
  Boys: 1000000
  Girls: 1000645
Looks pretty even to me.

Besides, if you compute the girls/boy ratio mathematically, you get

  0/2 + 1/4 + 2/8 + 3/16 + 4/32 + 5/64 + ...
which does converge to 1.


This was recently released as an old Google interview question and sparked some controversy.

This MathOverflow page [1] is a good (opinionated) summary. The best answer's author believes that with finitely many families the ratio actually doesn't work out evenly, but does converge to 50/50 with infinitely many families.

[1] http://mathoverflow.net/questions/17960/google-question-in-a...


That's specifically talking about the expectation of a ratio though. The expectation of the number of girls is always equal to the number of boys, even for finite families.

Expectation of a ratio != ratio of expectations.


Well, that's pretty obvious. If it involves an infinite sum, but you only have n people, you don't quite get to that infinity-th guy ;)


The answer suggested that even the expected value is never going to be 1/2 but instead something similar to 1/2-1/(4k) for k families which stop having children after the first boy. So, it's a bit more sophisticated than that involving situations where you test the average percentage of an infinite number of islands with k families each.


Maybe the clearest way to see it is that the expected number of boys is one (obviously--there's always exactly 1), and the expected number of girls is also one (1/2 + 1/4 + ...) since the prob. of (at least) one girl is 1/2, and the prob. of a second girl is 1/4, and so on.


I agree. This the first explanation that's made me fully understand and accept this problem.


Hmm. The handful of times I tried it I always got a smaller number for the girls than the boys. Just goes to show sample size is important... :)


You should maybe consider tracking which images are more likely to lead to a correct curtain selection. Then run an additional survey where subjects rank the same set of photos for hottness/arousal level, and see if there is a correlation.


Can somebody who knows math comment - There is a 5 % difference on a sample of 700. Not huge, but that seems statistically significant? Please post the source code so we can verify, and try this ourselves...


Assuming each trial is independent and the experiment is a Bernoulli experiment (e.g. akin to flipping a coin 700 times), the probability that you will get a result within 5% of the expected mean (50%) is 81.4%. Remember, though, that the probability of getting EXACTLY 50% is only 3%. The probability of getting exactly +/- 5% is about 2.5%.

So, you have about the same chance of getting that result as the theoretical. That by itself wouldn't mean anything, though - we need more information on the experiment. The best impromptu way to tell if it was significant would be to look at the distribution of the success rates of individual people.

@Parapsych - What kind of data are you logging and would you be willing to release that?


Currently down to a 0.5% difference with samples of a bit over 3000. Seems pretty insignificant to me.


At 8700 samples, it's 0.5% in favor of predicting non-erotic. Yup, seems pretty insignificant now.


likely to happen once in 50 experiments or so.

I think we need more samples to gauge significance.

Why do you need to try this offline? I'm not opposed to the idea, just curious.


Not offline, just on our own servers, so we can be sure it's random. But I didn't realize it was written in Javascript, so anyone can inspect the code.

I don't like that it shows you your percentage as you go. Aren't people more likely to quit when their Porn finding skills are higher?

Also, maybe i've been spoiled, but some of the 'erotic' pictures don't seem that erotic.

However... it seems like the #'s are evening out now, both around 51%

I think with a bit of re-design this could make for a great, and useful experiment.


Whether the picture appears on curtain 1 or 2 is predetermined, and the server provides proof in the form of a hash. You can see that on the bottom under your stats.

Yeah, I had a tough time finding erotic pictures. If you have a better idea of where I can find some to hot-link, also for gay / female audiences, lmk.


What are you talking about, of course I have no idea where to find those kind of pictures... although, and this is pure speculation, a Google images search with safe search turned off might return some interesting results.


> likely to happen once in 50 experiments or so.

How many hypotheses did he investigate? I seem to remember reading that he said he had investigated a fairly large number of them before finding this one.

If he investigated many different ways that people might manifest ESP only to find negative results in all but the porn study, then the odds change a bit. I mean, suppose you have 50 studies and a 1/50 chance of something like this--you'd have a 63.6% of ending up with a study like this one.


Is anyone actually taking this _really_ seriously? I am still waiting for the prank to be revealed...


What do you mean?

Somebody read about an experiment with surprising results, found out that it would be possible to turn the experiment into a website and did just that. I think that’s great.


I am talking about the original experiment. I am wondering whether people actually give ESP a serious possibility.

I am all for running experiments and finding out new things, and if this really happens to be a ground-breaking new discovery, great! That being said, what's more likely? That someone just _revolutionized_ physics and completely changed our concept of time, OOOOOR that there is something wrong with the experimental methodology? I don't know about you, but my 23 years on Earth make me think that the latter is quite a bit more probable...


I think it’s rather unlikely that ESP is real. It’s a reality of statistics that scientists will from time to time get wrong results; that and possible methodological problems leave all scientific results (except maybe the most obvious ones) up in the air until they have been confirmed again and again and again. (Psychology could also pick a smaller alpha value like maybe physicists and avoid being wrong more often but it’s questionable how practical such a change would be.)

Still, this is a neat DIY experiment. There is quite a bit you can criticize about the methodology but that discussion was pretty fun. Oh, and this experiment doesn’t even seem to confirm ESP. (I think. I didn’t break out the calculator.)


Honestly, I'm beginning to wonder if it is actually an experiment in the extent to which the scientific community will accept or at least consider ludicrous claims because they come from an authority figure.

EDIT: And I'm not saying that these claims shouldn't be tested. But it would be interesting to see the way people react. Hesitation, for example.


You are more likely to quit after finding porn. That is the trick.

It is reminiscent of the Martingale gambling strategy.


That seems to be a plausible explanation. I am still puzzled how the work ended up being published, though. Surely, the reviewers must have thought the same?


I just saw 2 pics and they were definitely not erotic. Maybe that explains the failure.



There is a big hole in this experiment. Think about it, let's say the future me choose 1 curtain in round 5.And I was wrong so I see nothing and move on to round 6. And the current me reaches round 5. Since in the future, i do not see any sexual photo, there's no future (arousal) information coming back to help me. (well, maybe the waiting punishment may discourage me to pick the same one). If I got to see the sexy photo even if i pick the wrong one (with time delay to separate it from picking the right one), then I might be motivated to send back my arousal feelings back to the past so that i can see the picture without waiting.


anecdotally i was able to get 2/3 of porn and around 60% non-porn over 60 rounds...not statistically significant in itself, but piques my interest in this line of thought

pie-in-the-sky thinking: is there some 'quantum immortality'-style argument that can be made for this sort of effect? quantum immortality is a somewhat fringe many-worlds-quantum-physics argument that an observer can never experience death and thus will always find him/herself in a universe in which they are alive (e.g. schrodinger's cat will always find itself in a universe where the atom did not decay). that is, in certain situations, a random event (e.g. decay of atom) would seemingly cease to be random (e.g. from the POV of schrodinger's cat) due to its consequences in the future (cat death by fumigation).

also, if this arousal-esp-effect actually is real (obviously exceedingly unlikely due to how bizarre its implications would be) i wonder if the human choice element would even matter; i'd like to see a similar experiment where everything is the same but there is no human choice and the curtains are just randomly chosen. the effect (if it actually did exist) might be due not to somehow arousal traveling backwards informing our consciousness but somehow arousal traveling backwards to influence what universe we find ourselves in.


I think the reason for the ESP is that people can decide to stop while they are ahead. The only legit way to do it would be to present a predetermined number of pictures and throw out the results if the entire sequence is not finished.

This is the same problem as testing for statistical significance too early.


judging from my own behavior, I think the bigger effect is quitting after a long string of losses, but YMMV


There is a nice paper explaining why the "PSI paper" is a sign that psychologists must adopt better statistics: http://www.ruudwetzels.com/articles/Wagenmakersetal_subm.pdf

There is a really nice paper that finally explained to me why Bayesian statistics might be superior to frequentist ideas for these purposes: http://pcl.missouri.edu/sites/default/files/Rouder.bf_.pdf


I don't know. Some of those nonerotic photos are doing it for me :)


Not sure if this is a sleight on myself or to the study, but I did not realize there were non-erotic photos in this study until I read your comment. I was confused with the nonerotic stat being presented below the erotic ESP stat during the study iterations.


Well done! I really wanted to do this myself :D


:) Glad you enjoyed it.


Any plans to do the other test too?


Now I do. Which one should I do?


The one where you show a bunch of nouns (around 25 I think). Then ask the user to type in as many as they can remember. Then make the one group look at the nouns again after the test, and the control group just left alone.

If his theory is right, the group that studied after the test should do better I think.


Let me guess, this is actually a disguised paid-referrer site for Naughty America.


I don't understand why you're making us wait 10 seconds?


I'm sure it has nothing to do with the big affiliate link on each picture.


I thought I had to put some delay, so as to prevent users from blowing through the experiment.

I'm not sure what to set it as. What seems appropriate to you?


Well, IF there's any future-reading effect to be found, and IF it diminishes over time, then shorter delays would show a stronger effect.


paf paf paf




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