Thinking Allowed

The Dangers of Common Sense
by Jon Thompson

It’s been said that what sets genuinely convincing mentalism apart from the pack is its presentation, and I agree. Effective presentation persuades the spectator to see things your way, while believing otherwise. Whether it convinces her that you have genuine paranormal abilities, are using advanced psychological techniques to influence and read her, or somewhere in between makes no difference. Regardless of your performance style, everything you do and say needs to work on the spectators’ mind to create an illusion that feels like reality.

We all start with the same basic model of brain between our ears. For want of a better term, let’s call it Homo Sapiens Brain (HSB) version 1.0. This remarkable 1.1kg of matter is by far the most complex thing in the known universe. That’s no exaggeration. Its design is mature, stable and reliable. Our brains are unbelievably more complex and advanced than those of other animals. Whereas there’s an invisible limit to the amount that other animals can understand about the world, we seem to have no such limits. We’re free to keep on developing from birth right up until the point of death. Your dog may be smart, but there’s a limit to his abilities. Your children, however, will always keep growing and developing.

Our HSBs enable us to find rich meaning in scant snippets of information. As we grow, this enables us to become increasingly good at coming to increasingly intelligent conclusions. In pre-history, we could work out whether that rustling in the bushes is a friend foraging for berries, someone from another tribe out to do us harm, or even a sabre tooth tiger. Just from that subtle rustle and shake leaves, we could survive and pass on our genes. The technique the brain uses for making such judgements is something very familiar to all of us: common sense. The problem is, common sense isn’t always the most appropriate way of seeing the world. You see, we’ve moved on, but our HSBs haven’t had time to evolve with us.

Modern life is frequently so complex and interconnected that discarding preconceptions and thinking through a situation logically is in many cases the best course of action, but this is difficult, tiring and no fun at all. Going with our common sense is the path of least resistance, but it’s a path we should be careful of taking. In his book “Your Brain – The Missing Manual”, Matthew MacDonald has this to say about common sense:

“The brain is an expert in common sense, which is the set of knowledge that everybody knows to be true because nobody wants to think about it anymore. Common sense has a pleasant face and a nasty underbelly. The good side is its blistering speed...The downside is its paunchy logic. In complex situations, common sense is all too often reduced to quick-thinking stupidity.”

Many of the psychological principles we can use to influence the spectator involve exploring the assumptions made by the brain when in “common sense mode”. Luckily, the brain is in this mode for most of the time, regardless of whether we believe otherwise or not. The errors in thinking this gives rise to create behaviours and beliefs about what’s going on that can be seriously at odds with the way things really are.

For instance, a stranger yells an urgent “Excuse me!” in a busy shopping street and people naturally turn round thinking the shout is directed at them. If you also turn towards the voice, you could be falling for a particularly reliable error called the personal validation fallacy.

Some people find it quite difficult to ignore the shout, even though the probability of it being directed at them is vanishingly small. This is nothing to do with ego. In fact, deliberately ignoring the shout will give rise to real mental anguish in some people. They may feel guilty about not helping someone they believe to be in trouble, for instance, or believe they’ve missed an opportunity to be helped themselves; the stranger maybe about to return a dropped wallet or purse. The shoppers that turn may even believe they’ve done something wrong. This is the same principle, the personal validation fallacy, and it also gives cold reading it’s power to convince.

Common sense thinking takes that undirected call and turns it into an internal representation that makes perfect sense in the blink of an eye. Whatever the meaning each person that hears it finds in the call, it places him at the centre of the action. It’s directed at him until he can see that it’s not by turning to find out. For some, the feeling simply can’t be dismissed without a lot of logical thought. How might you exploit that pathological from of curiosity to make a spectator act in a certain way?

Another error of common sense thinking that has a powerful hold over us is the Illusion of Control, which tends to influence people’s behaviour in ways that defy logic but which seem perfectly rational to them at the time. Watch closely the next time you play a game involving dice and an opponent needs to throw a high score to avoid something bad. There’s a very good chance she’ll shake the dice for longer than usual. That’s the illusion in action. In magic and mentalism, exploit it by handing the spectator control aspects of the effect that do nothing. The illusion will help make that supposed control seem to be capable of influencing the outcome. I’ve always wondered why people dismiss self-working mechanisms when the illusion of control exists to enhance their presentation, possibly even to the point of reality!

These are just two examples of how common sense thinking can be used to deliberately lead spectators into erroneous beliefs and behaviours. The ease with which we make such mistakes coupled with their seeming invisibility makes them the mentalist’s best friend after his library – and his own HSB, of course.

Jon Thompson