By Manuel Martín-Loeches Garrido - The Conversation
The human brain is not looking for the truth, it is looking good. Their study has led us experts to conclusions that are uncomfortable, but help us understand ourselves better.
The Whole Truth (or Not)
The human brain is a wonder of nature. It has been able to take us to the Moon, and it won't be long before it does so 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's the same brain that, when it makes planes as big as the Airbus A380, with a capacity for more than 500 passengers and exquisite engineering, omits the number 13 in the row of seats because "it's bad luck".
To understand why this is so, you have to know the whole truth about our brains. And this implies realizing that the processes that underlie our decisions are mostly – if not all – unconscious.
Free Will Is Not So Free
In the 1970s, psychologist Benjamin Libet showed that what we call free will was not as we had painted it. Electrodes placed in the right place on his participants' heads allowed him to discover that the brain initiated actions some time before they were aware that they were making the decision to carry them out.
When we make a decision, we think we've weighed the pros and cons, and we've matured our response. But experiments show that, normally, we don't know exactly what led us to make a decision.
Usually, in fact, the reasons for doing what we do are found after the fact; that is, we justify our actions once they have been done.
The evidence also shows that we defend our decisions above all else, even if we don't know what led us to them.
This way of being in our brain was called "the interpreter." With this name, the expert in the study of the mind Michael Gazzaniga highlighted that the brain is continuously interpreting reality, finding a reason for being 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.
The human brain seeks to look good
Gazzaniga discovered this when studying patients with the brain 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 primarily perceives what is to our right, while what is to our left is processed by the right. Likewise, the left hemisphere handles the right hand, and the right the left.
When we speak, moreover, we do so mainly with the left hemisphere, so with the brain divided 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 saw an object and was asked to choose an image related to it, the left hand picked up the correct image. As for the left hemisphere, the one who speaks, he watched the action without having the slightest idea why that was the right 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, for he was totally ignorant of the true one, but he was determined to give an explanation, however far-fetched.
This mechanism turned out to be very human, and not just typical of people with split brains. This is how all of humanity functions in its most everyday reality.
It's interesting to note that the interpreter never said "I don't know." Saying "I don't know" doesn't seem like the most humane response, even if it's the most reasonable in principle. And this is especially true when it comes to justifying our actions.
Strategies for Persuading
Truth is not the most important thing, but to be satisfied with a more or less credible, acceptable explanation. Acceptable to oneself and others, even if it is not true. As Hugo Mercier and Dan Sperber say, the reasoning strategies of our species 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, we usually cannot afford to waste time, but rather make quick and effective decisions, automatically, weighing a multitude of reasons at the same time. Most of them we will be little or not at all aware of, because to be so would require a lot of time and effort. It doesn't matter, we'll find a way to justify ourselves if something we've 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.