The Allure Of Simplicity

How the hardwiring of our brains makes us dupes

Image credit: New Statesman

We humans haven’t been on this planet for very long: perhaps four hundred thousand years as a distinct species. Which is the merest blink of an eye in geological terms. Our forebears were, like us, group primates surviving on the margins and eking out a living much as present-day baboons and chimps still do.

Like all species, we’re highly adapted to the environment we evolved in. And for at least 95% of our evolutionary history, that environment was the African savannah and the primordial forests of Eurasia. The challenges were largely unchanging: avoid predators, find food, compete with rivals for resources and mating opportunities, collaborate in order to survive. And most of all: don’t expend unnecessary energy.

Because in a world of sparse and uncertain calories, conserving energy can make the difference between life and death.

Our problem is that the human brain can consume up to 30% of the body’s blood glucose when actively at work. All of us have had the experience of feeling unusually hungry during the first days in a new job or after studying intensely for several hours. This is because our brain is hard at work assimilating new information and burning up those blood sugars.

But for at least 95% of our evolutionary history, those blood sugars would more likely have been needed to power our muscles to evade predators and forage for food. And unlike today, food was often scarce.

So we’ve evolved to do as little thinking as possible. Hence we prefer simple ideas to complex reality, and once we’ve managed to grab hold of a concept we cling to it tenuously and generally reject information that would indicate our beliefs are false. Because this conserves calories by reducing to the bare minimum the amount of thinking we have to do.

This was fine when we were back on the African savannah or in the primordial forests of Eurasia. It didn’t really matter if we believed in invisible magical creatures, thought that fire was alive, and imagined that you had to perform an elaborate ritual before napping a piece of flint. Our brains were “good enough” for the situation we evolved in, and nature works with good enough.