Why the Human Brain Did Not Evolve to Accurately Represent the True Nature of Reality

BY VICTOR S. JOHNSTON

Most of us believe that we live in a world full of sounds, colors, smells, and tastes because that’s what we experience every day of our lives and there appears to be no reason to think otherwise. However, to understand the human mind we need to abandon this naïve realism and come to accept the fact that our conscious experiences depend on the nature of our evolved neural organization, and not on the actual nature of the external world that evokes those experiences. This idea is so contrary to our common sense that few rational people would consider such a proposition to be an important insight that is essential for understanding our functional mind, but it is.

Although the external environment is teeming with electromagnetic radiation and air pressure waves, without consciousness it is both totally black and utterly silent. There is absolutely nothing that we can see, think, feel, or know that does not depend on the workings of our conscious mind. It is involved in every aspect of our daily lives; it defines who we are and the way we experience the world around us.

However, the human brain did not evolve to accurately represent the true nature of reality; it evolved for the sole purpose of enhancing the survival of our genes. This Darwinian perspective has profound implications for understanding the functional value of our conscious experiences. From this viewpoint many simple questions acquire a whole new meaning. Is sugar really sweet? Do rotten eggs really smell bad? Is it just by chance that waste products, like our feces and urine, smell and taste unpleasant? Why do we have so many different feelings, such as love, pride, fear, anger, and sadness? Why are our most intense feelings, such as orgasms, experienced when we are closest to reproductive success? When our sensations and feelings are viewed as emergent properties of biological brains, and not fixed or rigid properties that preexist in the external world, then they can evolve over generations.

The Greek philosopher Democritus is credited with the idea that all matter is composed of indivisible elementary particles that differ in size and shape. He called them atoms. We now know there are 118 different atoms organized into the periodic table that is displayed on the walls of high school chemistry labs. In the era of Democritus the idea that wine and spears, trees and elephants, rocks and human bodies, were all built from combinations of atoms was beyond belief. If everything was built of the same stuff, how could the proper ties of butterflies be so different from those of plants?

Illustration by Ástor Alexander

Of course we now know that atoms of carbon, hydrogen, oxygen, nitrogen, and phosphorus can be arranged into a complex DNA helix, that in turn dictates the structures of proteins, and ultimately the design of trees, butterflies, and human beings. These living organisms possess emergent properties that are not present in their simple atomic structure. Emergent properties have characteristic traits. They are: (a) unpredictable attributes that arise from the complex interactions of many different components, (b) properties that are not present in their physical and chemical elements, yet do not break the laws that govern those elements, and most important, (c) are able to exert downward control that is functionally useful for the system’s survival. These are also the traits required for a conscious biological mind.