Why we can’t trust our intuition to guide us

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Image credit: stack overflow

Imagine an animal that lives in a world of movable squares. Some squares are black and some are white. As the animal moves across the squares its brain begins to register a pattern. Most of the time, when two black squares appear one after the other followed by a white square, underneath the white square is a pellet of food. So the pattern is: B->B->W = food (most of the time).

Any animal with a brain that’s hardwired to detect patterns will benefit from this situation because it will begin to form a heuristic: when hungry, look for two contiguous black squares followed by a white square. Any animal with a brain that’s not hardwired to detect patterns will be unable to benefit from the seeming regularity of this somewhat regular environment and will likely fare poorly. Ultimately only the animals with brains capable of intuitively recognizing simple patterns will survive and pass on their genes to their descendants.

As we’d expect, because all creatures live within ecosystems that necessarily contain elements of order, all animals with central nervous systems have brains that have evolved to perform pattern recognition. Thus the human brain, like the brains of corvids and of all mammals, is a highly sophisticated pattern recognition machines. Provided we’re operating within environments for which we’re adapted, the heuristics we unconsciously develop will usually be helpful.

But now let’s see what happens when environments change. Let’s take our black-and-white environment and shake things up. Let’s assume the animal we created for our thought experiment can make changes to its environment. Naturally it would begin to arrange the squares so as to maximize the number of two-black-one-white combinations, thus yielding more food more reliably.

For a while, all goes well. But because most creatures of this type will all be seeking to do the same thing for the very same reason, after some period of time the environment becomes very complex, with squares overlaying one another and unimagined new combinations arising. Some of these meta-combinations will turn out to be even more advantageous than the simple two-black-one-white sequence, which will lead to more such advantageous combinations appearing across the ecosystem even if the creatures themselves don’t recognize these more complex meta-patterns.

Quite soon, the creatures will depend on these complex meta-patterns even though they fail to see them or understand that they’ve become dependent on them. Unfortunately this means that during times of stress (such as a local insufficiency of food, or physical conflict between different members of the species), the creatures will naturally fall back on their hardwired instincts. They will begin to pull apart the complex meta-structures in search of the two-black-one-white sequence they’re evolved to look for. As a result, the additional food resulting from the meta-structures will disappear and many of the creatures will starve to death.

All despite the fact that if the creatures had left the meta-structures alone, there would have been enough food to feed all of them as usual.

Because they could neither see nor intellectually encompass the meta-structures, the creatures under stress destroyed the very thing they depended on for their survival.

Obviously we humans don’t live in a world of black-and-white squares. But we do live in a highly complex inter-connected world that is beyond the grasp of even the most intelligent and well-informed. Clever and informed people can abstractly understand in a generalized way the astonishing complexity of global trade and see how everything we rely on today depends on this vast but fragile web being maintained. Most people, however, give the global web of inter-dependencies no more thought than they give to their smartphones, automobiles, or even the clothes they wear and the beverages they drink.

We have, in reality, no more grasp of our world than the creatures living in their world of black and white squares. And so we’re just as ready to tear it apart when we find ourselves operating under stress.

It’s often fashionable for people who know nothing about evolution to propose that we should “trust our instincts.” This easy-to-grasp mantra has the appeal of simplicity, which is a quality perpetually beguiling for the human brain. But it’s profoundly mistaken.

Today, most people in the developed world (for which the OECD can stand more-or-less as shorthand) are fat. We now have more obese people in the world than underweight people. This is because “trusting our instincts” in a world of high-calorie foods all around us is precisely the wrong thing to do.

During most of our evolutionary history, calories were scarce and uncertain. Consequently we’re hardwired to eat whenever we can, and seek out high-calorie foods in preference to foods with fewer calories because for 200,000 years or more, every calorie was a good calorie. But today the opposite is true. Many people in the West, and most in benighted places like the USA and the UK, have appalling diets. The USA, in fact, has become the first place in human history where people are both obese and simultaneously under-nourished. McSlop and Kentucky Fried Cancer provide calories and protein but essentially no other essential nutrients. The USA is therefore witnessing a recurrence of rickets and scurvy; 25% of US children consume no vegetables aside from French fries and tomato ketchup (which is mostly high fructose corn syrup).

A survey in 2005 indicated that the typical British person consumes around 3g of fiber daily versus the official recommendation of at least 25g while consuming around four times as much saturated fat as recommended.

Back in 1900 the average US citizen consumed around 0.9kg of sugar per year; by 2003 that figure was over 100kg. Salt consumption has likewise skyrocketed over the same period.

As a result the average US citizen consumes 17 different prescription medications each year* in order to offset the effects of atrocious diet coupled to a complete lack of meaningful exercise. Half of all health care spending in the USA and the UK goes on treating weight-related diseases, all of which are totally unnecessary and entirely the result of poor lifestyle choices.

If we can’t “trust our instincts” for something as simple as the substances we put into our mouths, how can we possibly trust these same instincts when confronting more complex challenges?

The MIT physicist Walter Lewin was famous for bringing physics to life in his undergraduate lectures. A couple of his “party tricks” will suffice to show how the human brain is simply not evolved to deal with anything more complicated than was found on the savannah of Africa and the primordial forests of Eurasia.

I’m going to describe a couple of Lewin’s demonstrations and ask you to predict the outcome. Then we’ll see what actually happens.

Demonstration One: We have a glass box resting on a flat surface. Inside the box is a child’s balloon filled with helium, so it floats. The balloon has a length of string tied around its base and the string is attached to a weight resting on the flat surface at the bottom of the box. As a result, the balloon remains tethered, floating in the air, as shown in the diagram below. The entire apparatus is placed on a trolley. Now we will accelerate everything by pushing it as hard and as quickly as we can:

Question: in which direction does the balloon move as a result of us pushing the trolley?

Congratulations if you said the balloon moves towards the rear of the glass box. You trusted your instincts, just as over 95% of people do.

Unfortunately, your instincts were totally wrong.

Here’s what actually happens:

Our brains aren’t adapted to understand things we can’t see or touch. So our instincts often mislead us even over something as simple as which way a balloon will go.

Why does the balloon go forward when we expect inertia to move it to the rear of the glass box?

The phenomenon occurs because the balloon (filled with helium) is less dense than the air around it, which is mostly a mixture of nitrogen and oxygen. When we sharply accelerate the box, the air inside it becomes slightly more dense toward the rear (because of inertia) and therefore slightly less dense toward the front. The balloon therefore “floats” toward the front because the atmosphere is less dense there, thanks to the very inertia we incorrectly thought would move the balloon backward too.

Demonstration Two: We have a small plastic funnel, the kind you can use to pour wine back into a bottle; we also have a ping-pong ball. We turn the funnel wide-end up and place the ping-pong ball inside. Now we blow as hard as we can through the narrow portion of the funnel so the air from our lungs hits the ping-pong ball resting in the cup of the funnel, as shown in the diagram below:

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What happens?

Congratulations if you said the ping-pong ball moves upward. You trusted your instincts, just as over 95% of people do.

Unfortunately, your instincts were totally wrong.

Let’s make the experiment even simpler: while holding the ping-pong ball in the funnel with one finger, we turn the funnel upside-down so that, if we remove our finger, the ping-pong ball will fall to the floor. Now we blow through the funnel as hard as we can while removing our finger from the ball.

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What happens?

Congratulations if you said the ping-pong ball shoots out of the funnel toward the ground. You trusted your instincts, just as over 95% of people do.

Unfortunately, your instincts were totally wrong.

Here’s what actually happens in both scenarios:

When we try to expel the ping-pong ball from the upturned funnel, our breath passes from the narrow tube at the base of the funnel into the wider part of the funnel. This means the air pressure drops as it flows around the ping-pong ball. As a result of this area of low pressure (compared to the normal atmospheric pressure acting on the top of the ball) the ping-pong ball can’t move upward. It’s pulled back by the low-pressure area below and around its sides.

Now when we turn the funnel upside-down and blow, the very same thing happens: the low pressure area holds the ball in place, overcoming the force of gravity. Only when we run out of breath and therefore cease creating the low-pressure area can the ball finally succumb to gravity and fall downward.

Oh dear. If we can’t even trust our instincts for really basic stuff like this, how can we possibly imagine we can trust our instincts when it comes to far more complicated matters?

The fact is, our modern world is utterly unlike the environments for which we’re adapted. Evolution hasn’t caught up. We’re literally ape-creatures stroking magical devices that the overwhelming majority of us don’t understand in any way.

Not surprisingly, when we’re whipped into a state of mass panic by a media entirely reliant on manufacturing sensation in order to sell ad slots, we make atrociously poor choices. It doesn’t matter if most of us imagine these choices are rational and “for everyone’s good.” Remember: more than 95% of people fail to predict accurately the outcomes of the very simple experiments outlined above. This suggests strongly that the majority of people will likewise have false beliefs when it comes to the efficacy of hasty panic-induced behaviors.

Just like the creatures living in the world black-and-white squares, the moment we’re placed under stress we usually end up tearing apart the very things we rely on. History is replete with examples of short-sighted human behaviors that resulted in catastrophically low-quality outcomes, all because our brains aren’t adapted to handle complexity.

That may be worth bearing in mind during these difficult times of media-induced mass hysteria.


*US Surgeon General report 2015

Here are links to clips from Lewin’s lectures where he demonstrates the two phenomenon I’ve shamelessly stolen for my article (apologies in advance for the atrocious video quality):


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Anyone who enjoys my articles here on Medium may be interested in my books Why Democracy Failed and The Praying Ape, both available from Amazon.

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