Recent replies to "Extrasensory perception (ESP) fails the test"

Reply from Damien Samways

Damien Samways — Fri, 14 Mar 2008 15:57:46 -0000

I think getting to the nitty-gritty of the epistemology here is actually quite important, because it challenges us to consider whether these phenomena are in fact testable at all, and if they are, how.

Steven highlights the problem of trying to address these sorts of phenomena experimentally. The formation of a sturdy, testable hypothesis is, in many cases, simply not practical.

The inductive “absence of evidence” case is much weaker than it is for, say, measuring the effect of a drug on a physiological response. If hypertension patients treated with the test drug have BPs no different than placebo, we would conclude that the drug is ineffective. There are, of course, other possibilities (by some freak occurrence those patients just happen to be unresponsive; or the drug batch was dodgy; or the investigators got the tubes mixed up), but adequate controls can be put in place to really narrow the limits of alternative explanations until the most like explanation for the negative data is that the drug simply isn’t effective. Yes, it’s inductive, but induction can be strong enough to be practical, if not philosophically ideal (I think Steven mentioned this).

With ESP, such controls are not feasible, and so the inductive force of the “absence of evidence” is considerably weaker, and not at all forceful enough to allow a conclusion of “evidence of absence”.

Noah said,
“From a different perspective, if the same experiments were conducted on individuals claiming to be clairvoyant, with the hypothesis that they actually were, then this study would again have provided evidence of absence of ESP, if the subjects performed at chance level on the task.”

This hypothesis is problematic because it rests on the assumption that the self-proclaimed clairvoyants are telling the truth. If the experiment fails to show evidence that they are clairvoyant, the possibility that they are lying immediately renders the initial hypothesis invalid. This is a paradox that plagues sociobiology and psychology (I think that there’s a name for it, but I forget).

Reply from Steven Ericsson-Zenith

Steven Ericsson-Zenith — Tue, 04 Mar 2008 23:55:57 -0000

“ESP does not exist” is no kind of hypothesis. It assumes a priori that there is some phenomena to examine. It is an assertion no better than the assertion “ESP exists.” Both statements are without meaning from a scientific point of view.

The study itself is vacuous. It experimented with no phenomena with which the study was supposedly concerned and observed no evidence worth reporting.

Reply from Noah Gray

Noah Gray — Tue, 04 Mar 2008 22:11:51 -0000

What if the hypothesis was: “ESP does not exist.” Then, this study has provided evidence in support of this hypothesis, or rather, evidence for the absence of ESP, not an absence of evidence that ESP does not exist.

From a different perspective, if the same experiments were conducted on individuals claiming to be clairvoyant, with the hypothesis that they actually were, then this study would again have provided evidence of absence of ESP, if the subjects performed at chance level on the task.

I think that is enough semantics discussion for one thread, and I don’t intend to return to this issue. I hope that we can discuss something else regarding this study.

To start off in that direction, here goes: As I mentioned in the post, I think that the study has a clever design, and based on everything we have available to us today for use on human subjects, these are about the most relevant techniques around. Are there alternatives that you would suggest that could potentially provide more meaningful data?

Reply from Steven Ericsson-Zenith

Steven Ericsson-Zenith — Tue, 04 Mar 2008 20:17:05 -0000

Let me correct the wording of part of my prior response (and edit function would be useful). It should read:

As to the relevance of the methods used in this study of the hypothesis, that I have not seen clearly stated, they seem to me to be little more than digging around in a dark room in Mexico with a tooth pick and the expectation that you will find an elephant.

Reply from Steven Ericsson-Zenith

Steven Ericsson-Zenith — Tue, 04 Mar 2008 19:34:47 -0000

You are confused. “Evidence of absence” is simply an impossible scientific criteria.

What I think you mean to say is that the study failed to verify an hypothesis for which there was no empirical evidence in the first place.

As to the relevance of the methods used in this study the hypothesis (which I have not seen clearly stated) seems to me to be little more than digging around in a dark room in Mexico with a tooth pick and the expectation that you will find an elephant.

Reply from Noah Gray

Noah Gray — Tue, 04 Mar 2008 19:04:41 -0000

What standard are you discussing? Of course, negative data exist!! My standard for evidence is based on scientific experimentation. There is no doubt in my mind that evidence for absence can be produced; it simply depends on the experiment. If you will take the time to peruse the scientific literature, you will find it littered with experiments demonstrating the evidence of absence. It is the bread and butter of science (often to the disdain of researchers trying to publish positive results). Again, this concept differs from not finding evidence at all.

Returning to this study on ESP in particular, I still do not understand your position. No matter what I write, you seem to imply that I support such research into pseudoscientific principals. I don’t. This study failed to find evidence for the existence of ESP. Therefore, does this prove that is doesn’t exist? No. So has it added to our knowledge of the paranormal? No. It has simply informed us how NOT to conduct an experiment to test for evidence of absence regarding ESP. An incremental step forward, wouldn’t you say?

Going back to your tooth fairy comment. I can set a hidden camera up facing a child’s pillow all night, and probably capture footage of her mother sneaking in to remove the tooth, while leaving behind some money. Voilà! Evidence of absence. Or from an alternative viewpoint, evidence that a parent/guardian is the tooth fairy. I think that I can get that study done without the help of the taxpayers.

As for tackling the existence of God, if science had the means and appropriate design to test for this, I would definitely support it. Do I think that at this time we do? No. Therefore, I would agree that going down this path would not be fruitful.

Reply from Steven Ericsson-Zenith

Steven Ericsson-Zenith — Tue, 04 Mar 2008 18:29:43 -0000

The problem is that your standard of evidence supports mere invention. True science starts with speculation but if you do not base such speculation on empirical standards then you open the flood gates for irrational thought.

For example, by your standard both God and the Tooth Fairy are worthy of scientific consideration.

Reply from Noah Gray

Noah Gray — Tue, 04 Mar 2008 17:34:32 -0000

I don’t understand your concern, Steven. It is simply good science to state that one cannot dismiss something simply because one failed to find something.

The only way to be sure is to provide evidence of absence. Although challenging, people do it all the time (so-called negative data). All negative data is evidence of absence, in a sense. If science has yet to provide evidence of absence for any particular irrational belief, but has simultaneously failed to provide any evidence supporting its existence, it looks like there is more work to be done. Despite that literal viewpoint, my bigger question from the above post was whether scientists should be using limited research dollars and resources to work on problems such as the existence of the paranormal. If it is private funding, fine, but I don’t believe that public funding should be used to address such questions.

For the record, the above studies were supported by the Bial Foundation and the Richard Hodgson Memorial Fund. I assume that they are aware of how their money was spent.

Reply from Steven Ericsson-Zenith

Steven Ericsson-Zenith — Tue, 04 Mar 2008 16:52:54 -0000

I confess that I am a little worried by the “absence of evidence is not evidence of absence” argument – as rhetorically perfect as it is. This rationale simply supports any irrational belief.

Reply from Noah Gray

Noah Gray — Tue, 04 Mar 2008 15:45:25 -0000

By established, I did mean people who claimed to have such special abilities.

Although, there is a slippery slope here, since using “gifted” individuals could increase the potential for experimental manipulation by nefarious advocates of ESP, leading to a study scientifically “proving” ESP when in fact, the subjects cheated. Having false positive data is almost more dangerous than having no data at all.

Reply from Leonie Welberg

Leonie Welberg — Tue, 04 Mar 2008 11:54:50 -0000

Dear Noah,

Regarding your remark that “participants were randomly selected as opposed to using individuals with established paranormal talents”, I’d be curious to know how such supernatural talents are ‘established’ in the first place? As far as I know, nobody has managed to do this, not even James Randi in his million-dollar challenge (www.randi.org). Anyone can claim to possess paranormal abilities, but when such people are tested in controlled circumstances they don’t perform above chance level. They always have plenty of excuses of course (interference by negative energy emitted by the skeptical scientist being one).
I agree that absence of evidence does not necessarily mean evidence of absense, but in the case of ESP (and all paranormal claims) it should be up to the claimant to prove that ESP exists.

Reply from Noah Gray

Noah Gray — Thu, 07 Feb 2008 16:34:11 -0000

I think that Emmanouil raises an excellent point. To facilitate the understanding of such “gifts”, indeed, why is it that so few (are there any?) individuals possessing supernatural talents actually allow scientists to better understand their abilities? Athletes that accomplish extraordinary physical feats are not shy to allow science to determine the mechanisms underlying their means of completing the Ironman competition, etc… Is this because their talents/physical attributes are actually measurable by modern science (arguably unlike ESP)? Or is it because there is a fear by those claiming to have ESP of being “outed”?

Reply from Emmanouil Froudarakis

Emmanouil Froudarakis — Thu, 07 Feb 2008 16:16:14 -0000

3. I agree with the notion that absence of evidence is not the same as the evidence of absence. Their results indicate that ESP probably is not a universal human characteristic.

2. fMRI is the best technique until present, since we have no evidence of where the ESP is received and fMRI can detect small changes in the whole brain volume.

1. Considering the scientist, it is clearly his decision based upon his fundings. Trying to find ways to study this question will lead to the development of better techniques, and if there is a case of ESP existence, it will be possible to prove. In the other case, science in general should focus in more fundamental questions (fortunatelly it does).

My opposition with this kind of questions is always another question: Why people with established paranormal talents don’t come front and help this world by letting science study them and thus discover any ESP? Although scientists should be open minded, there are questions like “is there a god?” that by their nature can’t be proven…

Reply from Betsy Pfister

Betsy Pfister — Sat, 26 Jan 2008 15:29:48 -0000

While I doubt the existence of ESP, I see no reason to discourage anyone “wasting their time” investigating it. Things that were once considered magical or mythical are now commonplace due to the application of science and technology. Maybe someone will come up with a technology-based ESP as a result of their interest. My doubts do not make it a waste of time unless, doubtful or not, it is absolutely untestable. And I’m not convinced that we can say that. As to this particular study, the flaws you noted may have made it a waste of time…the study just doesn’t demonstrate anything very useful.

Reply from Steven Ericsson-Zenith

Steven Ericsson-Zenith — Sun, 20 Jan 2008 00:41:12 -0000

Certainly scientists are wasting their time testing the claims of pseudo-science.

However, there are two separate issues here.

The first of these is addressing empirical claims. “Observed behavior” that is not consistent with current models do need to be inspected and eliminated by scientists whose work is related in some way.

The second issue is the sociological scope of the claim. If the claim is widely supported by an irrational belief then we have a social responsibility to address the issue.

The real question is, should the public waste the time of scientists by supporting the claims of pseudo-science.

Since we have no really adequate comprehension of what sense is in the first place, it seems unwise to attempt to make any type of comparison. Sense is comprehensible currently only to the extent that a sense correlates to some consistent action on the part of the organism; I see the ball and catch it.

Reply from Damien Samways

Damien Samways — Tue, 15 Jan 2008 00:26:59 -0000

“Although interesting, there are plenty of problems with this study, the most glaring being that participants were randomly selected as opposed to using individuals with established paranormal talents.”

Absolutely. On the basis of this methodology, you could randomly select a group of people who were not pro baseball players and erroneously conclude that humans aren’t capable of hitting a home-run.

I tend to agree with Ray Hynman (and the article you link to) that attempting to test ostensibly “paranormal” phenomena empirically is conceptually problematic. And setting up flawed experiments to test such phenomena doesn’t do any justice to science.

I Want To Believe, but some things are best left to Mulder and Scully, IMHO.