The Brain Is a Strange Concoction of Different Parts

Human nature is both hugely complex and contains several Achilles' heels.

Reviewed by Lybi Ma

Imagine that you have been hired by a car company and given the task of creating a new revolutionary electric car. The task comes with a peculiar twist: you must start with a T-Ford from 1908. Inserting a brand-new engine is therefore out of the question, you must use the T-Ford's engine and adjust it. The same goes for the tires, the cabin, the brakes, and the doors; everything must be based on the T-Ford. As if that wasn't enough, every small change you make, from the smallest screw, must result in a car that is at least as good as before the change.

It's not a wild guess that the car you end up with would be a strange concoction of disparate parts. And it is no wild guess that the result would have been different, probably better, if you had been able to start with a blank slate and not be limited by the T-Ford.

However, this is exactly how the process that developed humans and our brain, that is, evolution, works. Evolution starts from something simple and makes small changes. Successively, through many small changes of which each must lead to something at least as viable, species evolve. Evolution can never start with a blank slate; it can only modify what already exists. Nor can it plan and develop something that a thousand generations into the future will be useful as every small change along the way must lead to something that is at least as viable.

The brain is therefore a strange concoction of different parts. This has a very important consequence: our most advanced mental functions, such as moral reasoning, are often based on primitive functions that have evolved to solve a new task. For example, there is a part of ​​the brain, the insular cortex, that protects mammals from rotten food by creating a feeling of disgust. The same area is activated in humans when we are disgusted by rotten behavior. Genocide is often preceded by disgust-based rhetoric for exactly this reason: when you get disgusted, you stop thinking rationally. You don’t just ignore or dislike what disgusts you. You hate it and want to get rid of it. Historical monsters such as Adolf Hitler have exploited this vulnerability in our psychology when they compared humans to cockroaches, bacteria, and contagion, all of which trigger disgust. Nazi Germany and the Holocaust is not the only time when this neurobiological overlap contributed to unimaginable atrocities. Disgust-based rhetoric paved the way for the Rwanda genocide in 1994 when at least 800,000 humans were killed.

My point is that when we put the brain on a pedestal and think of it as Mother Nature’s greatest wonder we are only partially right. Yes, the brain is without doubt incredibly impressive but no engineer in their right mind would have put together something as strange as what we have inside our skull. An engineer would have built a system for moral reasoning that is not sensitive to disgust, a system that could not be swayed by such rhetoric. But evolution is no engineer and could never do that. Since evolution could not start with a blank slate it used disgust avoidance as a basis for moral reasoning and, in the process, created a psychological Achilles' heel in us.

In light of the messy and strange construction of the brain, it is no wonder that human nature is both hugely complex and contains several serious Achilles' heels. This is exactly why we need to learn about the brain. With better knowledge, we can work around its limitations and vulnerabilities. The more we learn about the brain and the biology behind our behavior, the freer we become from it.