The human brain does not seek the truth, what it seeks is to look good. His study has led us experts to conclusions that are uncomfortable, but help us understand ourselves better.
The human brain is a wonder of nature. It has been able to take us to the Moon, and it will not take long to take us to Mars. Humanity has managed to explore the ends of the world, the solar system, the universe, and understand them in depth. Yes, the human brain is prodigious. It is, without a doubt, what makes us the most intelligent species on the planet. But it's not perfect.
It is the same brain that, when manufacturing airplanes as large as the Airbus A380, with a capacity for more than 500 passengers and exquisite engineering, omits number 13 from the row of seats because “it is bad luck.” To understand why this is so, we have to know the whole truth about our brain. And this implies verifying that the processes that underlie our decisions are mostly – if not all – unconscious.
In the 1970s, psychologist Benjamin Libet demonstrated that what we call free will was not as we had painted it. Electrodes placed in the appropriate place on the heads of his participants allowed him to discover that the brain initiated actions some time before they were aware of making the decision to carry them out.
When we make a decision we believe we have weighed the pros and cons, and have matured our response. But experiments show that we usually don't know exactly what led us to make a decision.
The usual thing, in fact, is that the reasons for doing what we do are found a posteriori; That is, we justify our actions once they are done. The evidence also shows that we defend our decisions above all else, even if we do not know what led us to them.
This way of being of our brain was called “the interpreter.” With this name, the expert in the study of the mind Michael Gazzaniga highlighted that the brain is continually interpreting reality, finding a reason for all things. But he also doesn't care if his interpretation is true or not: it is enough for him that it is satisfactory, apparently good.
Gazzaniga discovered this when studying patients with their brains split, that is, surgically divided into two separate hemispheres as a result of treatment for recurrent epileptic seizures.
Each hemisphere perceives and acts on one half of the world. The left mainly perceives what is to our right, while what is to our left is processed by the right. Likewise, the left hemisphere controls the right hand, and the right hemisphere controls the left.
When we speak, furthermore, we do it mainly with the left hemisphere, so with the split brain it is as if we had two people, one who speaks and the other who does not utter a word.
In Gazzaniga's experiments, when the patient's right hemisphere viewed an object and was asked to choose an image related to it, the left hand picked the correct image. As for the left hemisphere, the one that speaks, he observed the action without having the slightest idea why that was the correct image. But when the patient was asked why he had taken that image, his left hemisphere responded by inventing a reason. He was never right, since he was totally unaware of the true one, but he was determined to give an explanation, no matter how far-fetched it might be.
This mechanism turned out to be very human, and not only typical of people with split brains. All humanity functions like this in its most everyday reality. It is interesting to note that the interpreter never said “I don't know.” Saying “I don't know” does not seem like the most humane response, even though in principle it is the most reasonable. And this is especially true when it comes to justifying our actions.
The truth is not the most important thing, but rather being satisfied with a more or less credible, acceptable explanation. Acceptable for oneself and for others, even if it is not true. As Hugo Mercier and Dan Sperber say, our species' reasoning strategies did not evolve to arrive at the truth, but to persuade others that we are right.
The explanation for all this, as I explain in my latest book, is that our brain is hypersocial. It became great not to take us to the Moon, but to face the great challenges of living in society, of living with a large number of individuals with whom we sometimes cooperate and sometimes compete.
In these circumstances, the usual thing is that we cannot afford to waste time, but rather make quick and effective decisions, automatically, weighing a multitude of reasons at the same time. Of the majority we will be little or not at all aware, because being aware would require a lot of time and effort. It doesn't matter, we will find a way to justify ourselves if something we have done seems wrong in the eyes of others. That's what the interpreter is for: to preserve at all costs something as valuable as our self-esteem.
