23 October 2009

How science differs from pseudoscience - Part 1

A recent Science Weekly podcast of the Guardian included a lengthy interview with Chris French, a professor at the University of London who is studying "anomalistic psychology", defined as the psychology of paranormal beliefs and experiences. Regarding the commonly heard statement that one wouldn't believe in ghosts or angels (or whatever) unless one saw one with one's own eyes, professor French said the following (my transcription): "My attitude is even if you do think you see one with your own eyes then that doesn't really prove it."

Upon hearing this, I was initially puzzled. How can we discount our own observations? After all, the 3 fundamental sciences, physics, chemistry and biology, their theoretical branches notwithstanding, are essentially experimental and observational and experiments and observations in general, even when heavily aided by instruments, rely more on vision than any other senses. Probably because of that, blind scientists are rare, very rare; in fact, the only one I know is the remarkable Geerat Vermeij, a malagologist, incidentally, who has been completely blind since early childhood (more info).

Of course, scientists sometimes make erronous observations. Nevertheless, scientists' visual observations are normally not considered suspicious or unreliable. If I claimed that I saw a snail doing something and explained how it was doing it, my peers would believe me. But why should we accept the observations of a scientist, and be skeptical of those of a pseudoscientist? Double standards imply dishonesty, but scientific research is supposed to be an honest and a democratic process.

A scientist is more believable unless the reported observations are highly unusual. That is the keyword. Where a particular observation or claim fits within the already established knowledge seems to be the crucial difference between the scientific observations and the paranormal "observations".

Part 2


xoggoth said...

Sanity is a relative thing and some of us certainly see things that don't exist.

When younger I regularly saw odd things, on one occasion a huge skull that rolled slowly out of a garden gate and disappeared, on another a thing with two tails and covered in matted fur that swam lazily over the road about 8 feet up. A lot of them happened during stressy periods, the latter occasion when I was on my way to school to take exams, and for that reason I doubt they were apparitions.

xoggoth said...

PS Wibble, wibble.

Anonymous said...

Yes, as Carl Sagan said: "Extraordinary claims require extraordinary evidence".

For example, if someone tried to claim in a science paper that there were 10 foot snails in your local Maryland woodland, other scientists would want not only to see some photographs, but some voucher material too, given to a major museum, so it could be examined by numerous scientists at will.

The problem with ghosts and extraterrestrials is that there is never any really good, really reliable evidence to back up the claims, and since the claim is so very extraordinary, the evidence has to be extraordinarily good also.

Susan J. Hewitt


Susan, yes, Sagan was right, of course, but I think the point Chris French was making is different. Suppose I see with my own eyes something that I think is a ghost. French's advice is that I shouldn't believe my own eyes in this case. I will write more about this in a future post.

pascal said...

Your discussion connects nicely to my recent posts regarding young-Earth creationism and flood geology.


Welcome back. I am printing your long post to read it later.

Anonymous said...

You are talking about whether we can trust what we think we see? How we can know what is an illusion or a hallucination, and what on the other hand is accurate seeing of physical reality? I think the same rules apply really. If it is something unusual enough to be almost incredible then you need at least photographs if not physical evidence to back up what you think you saw.

I think most of us once in a great while think we see something that actually has no objective reality or is a misinterpretation of physical reality, even if we are not psychotic. But how often does this happen in a scientific context? And when it does happen at any time in our lives, do we understand ourselves well enough to know that this apparent perception is not trustworthy? This concerns the very nature of reality and epistemology. I an very much looking forward to your next post about this topic.

Susan J. Hewitt

Michael said...

Ask a cop about the reliability of eyewitness reports ;-)

Most of us have experienced optical input that on more careful observation turned out out to be incorrect - just the other day I dodged a "person" walking on the freeway that turned out to be a plastic garbage bag.

I think French is simply saying that it would take more evidence than a single visual observation to convince him of the existence of a ghost. That's true for me as well.