Scepticism v credulity

Humans are pattern-seeking animals. We search for meaning in a complex, quirky, and contingent world. But we are also story-telling animals, and for thousands of years our myths and religions have sustained us with stories of meaningful patterns – of gods and God, of supernatural beings and mystical forces, of the relationship between humans with other humans and their creators, and of our place in the cosmos.

One of the reasons why humans continue thinking magically is that the modern, scientific way of thinking is a couple of hundred years old, whereas humanity has existed for a couple of hundred thousand years. What were we doing all those long gone millennia? How did our brains evolve to cope with the problems in that radically different world?

Those who were best at finding patterns (standing upwind of game animals is bad for the hunt, cow manure is good for the crops) left behind the most offspring. We are their descendants. The problem in seeking and finding patterns is knowing which ones are meaningful and which ones are not. Unfortunately our brains are not always good at determining the difference. The reason is that discovering a meaningless pattern (painting animals on a cave wall before a hunt) usually does no harm and may even do some good in reducing anxiety in uncertain situations.

So we are left with the legacy of two types of thinking errors: 1. Believing a falsehood and 2. Rejecting a truth. Since these errors will not necessarily get us killed, they persist. The belief engine in our brains has evolved as a mechanism for helping us to survive because in addition to committing Type 1 and Type 2 Errors, we also commit what we might call a Type 1 Hit: not believing a falsehood and a Type 2 Hit: believing a truth.

Most of us harbour a type of faith in science, a confidence that somehow science will solve our major problems—AIDS, overpopulation, cancer, pollution, heart disease, and so on. Some even entertain scientistic visions of a future without ageing, where we will ingest nanotechnological computers that will repair cells and organs, eradicate life-threatening diseases, and maintain us at our chosen age.

So hope springs eternal not just for spiritualists, religionists, New Agers, and psychics, but for materialists, atheists, scientists, and even sceptics. The difference is in where we find hope. The first group uses science and rationality when convenient, and dumps them when they are not.

For this group, any thinking will do, as long as it fulfils that deeply rooted human need for certainty. Why? Humans evolved the ability to seek and find connections between things and events in the environment (snakes with rattles should be avoided), and those who made the best connections left behind the most offspring. The problem is that causal thinking is not infallible. We make connections whether they are there or not.

These misidentifications come in two varieties: false negatives get you killed (snakes with rattles are okay); false positives merely waste time and energy (a rain dance will end a drought). We are left with a legacy of false positives – hallucinations we get just before awakening become ghosts or aliens; knocking noises in an empty house indicate spirits and poltergeists; shadows and lights in a tree become the Virgin Mary; random mountain shadows on Mars are seen as a face constructed by aliens.

The belief influences the perception. “Missing” fossils in geological strata become evidence of divine creation. The lack of a written order by Hitler to exterminate the Jews means that perhaps there was no such order … or no such extermination. Coincidental configurations of subatomic particles and astronomical structures indicate an intelligent designer of the universe. Vague feelings and memories evoked through hypnosis and guided-imagery in therapy evolve into crystal-clear memories of childhood sexual abuse, even when no corroborating evidence exists.

Scientists have their false positives – but the methods of science were specifically designed to weed them out. Had the cold fusion findings, to take a recent spectacular example of a false positive, not been made so public before corroboration from other scientists, they would have been nothing out of the ordinary. This is precisely how science progresses – countless identified false negatives and false positives. The public, however, does not usually hear about them because negative findings are not usually published. That silicon breast implants might cause serious health problems was big news; that there has been no corroborative and replicable scientific evidence that they do has gone almost unnoticed.

You have to lobby for your opinion to be heard. Then you have to marshal experts on your side so you can convince the majority to support your claim over the one that they have always supported. Finally, when you are in the majority, the burden of proof switches to the outsider who wants to challenge you with his or her unusual claim. Evolutionists had the burden of proof for half a century after Darwin, but now the burden of proof is on creationists.

It is up to creationists to show why the theory of evolution is wrong and why creationism is right, and it is not up to evolutionists to defend evolution. The burden of proof is on the Holocaust deniers to prove the Holocaust did not happen, not on Holocaust historians to prove that it did. The rationale for this is that mountains of evidence prove that both evolution and the Holocaust are facts. In other words, it is not enough to have evidence. You must convince others of the validity of your evidence. And when you are an outsider this is the price you pay, regardless of whether you are right or wrong.

Rumours begin with “I read somewhere that…” or “I heard from someone that….” Before long the rumour becomes reality, as “I know that…” passes from person to person. Rumours may be true, of course, but usually they are not. They do make for great tales, however. There is the “true story” of the escaped maniac with a prosthetic hook who haunts the lover’s lanes of America. There is the legend of “The Vanishing Hitchhiker,” in which a driver picks up a hitchhiker who vanishes from his car along with his jacket; locals then tell the driver that his hitchhiking woman had died that same day the year before, and eventually he discovers his jacket on her grave. Such stories spread fast and never die.

Caltech historian of science Dan Kevles once told a story he suspected was apocryphal at a dinner party. Two students did not get back from a ski trip in time to take their final exam because the activities of the previous day had extended well into the night. They told their professor that they had gotten a flat tire, so he gave them a makeup final the next day. Placing the students in separate rooms, he asked them just two questions: (1) “For 5 points, what is the chemical formula for water?” (2) “For 95 points, which tire?” Two of the dinner guests had heard a vaguely similar story. The next day another professor repeated the story to his students and before he got to the punch line, three of them simultaneously blurted out, “Which tire?” Urban legends and persistent rumours are ubiquitous.

Feats such as the bending of spoons, fire-walking, or mental telepathy are often thought to be of a paranormal or mystical nature because most people cannot explain them. When they are explained, most people respond, “Yes, of course” or “That’s obvious once you see it.” Fire-walking is a case in point. People speculate endlessly about supernatural powers over pain and heat, or mysterious brain chemicals that block the pain and prevent burning.

The simple explanation is that the capacity of light and fluffy coals to contain heat is very low, and the conductivity of heat from the light and fluffy coals to your feet is very poor. As long as you don’t stand around on the coals, you will not get burned. (Think of a cake in a 450°F oven. The air, the cake, and the pan are all at 450°F, but only the metal pan will burn your hand. Air has very low heat capacity and also low conductivity, so you can put your hand in the oven long enough to touch the cake and pan. The heat capacity of the cake is a lot higher than air, but since it has low conductivity you can briefly touch it without getting burned. The metal pan has a heat capacity similar to the cake, but high conductivity too. If you touch it, you will get burned.)

There are many genuine unsolved mysteries in the universe and it is okay to say, “We do not yet know but someday perhaps we will.” The problem is that most of us find it more comforting to have certainty, even if it is premature, than to live with unsolved or unexplained mysteries. The 14th–century friar William of Ockham said that if you have two competing ideas to explain the same phenomenon, you should prefer the simpler one. Suggesting coincidence, the paranormal, alien influences, magic, etc might appear logical in some instances, but a thorough examination of the event usually produces more believable results. Hence it is probably best to use deductive, inductive, abductive and intuitive reasoning in order to come to a satisfactory conclusion.