Why does the brain justify inexplicable decisions according to neuroscience?
Neuroscience and self-deception: how does the brain justify inexplicable decisions?
This intriguing topic was addressed in La Fórmula Podcast by neuroscientist Andrés Rieznik, who explored the phenomenon of how our brain becomes an internal narrator that justifies our actions, even when they lack a conscious explanation. This cerebral “interpreter” allows us to rationalize our decisions, a key mechanism for understanding cognitive self-deception, which plays an important role in mental health and in the way we perceive and respond to reality.
An interpreter in the brain: how the brain creates narratives to justify our decisions
Rieznik, a PhD in physics and a specialist in behavioral neuroscience, explains the role of a mechanism in the brain that he refers to as the “interpreter.” This interpreter operates as an internal narrator that generates a coherent story about our actions. Its function is key in the rationalization process, where the brain generates explanations for behaviors that, at first glance, do not seem to make sense or be justifiable.
Michael Gazzaniga, a pioneer in cognitive neuroscience, researched the phenomenon of self-deception in the 1980s. Through experiments with patients whose corpus callosum (the connection between the two hemispheres of the brain) had been severed for medical reasons, Gazzaniga demonstrated that each hemisphere could act and respond independently. In one of the experiments, patients received different visual stimuli in each hemisphere, such as the word “red” in one eye and “banana” in the other, and were then asked to draw what they had seen. Despite the verbal hemisphere not having access to the image of the banana, they drew it; however, when asked about the reason, they invented excuses. This phenomenon revealed that the brain invents reasons to justify behaviors without conscious explanation.
How the brain deceives us to protect our identity and reduce stress
The function of the interpreter in the brain is not only to justify decisions but also to protect our identity. By providing a coherent narrative of our decisions and actions, the interpreter allows us to maintain a unified view of ourselves. Without this ability for self-deception, we could experience anxiety and disorientation in the face of decisions we cannot explain. This mechanism is particularly useful in complex or stressful situations, where our brain must make quick decisions and justify afterward why.
Neuroscience suggests that this self-deception is necessary to maintain emotional balance. According to Rieznik, the interpreter “gives a sense of rationality and uniqueness to our behavior so that we do not go crazy.” This is because the brain needs to provide a comprehensible narrative, even when the information has not been processed completely or consciously. This is how the brain performs a balancing act between the perception of reality and the need to protect our identity, thus allowing us a more stable and less critical perception of our actions.
Cognitive reserve and the role of learning for healthy aging
One of the fundamental concepts in modern neuroscience is that of “cognitive reserve,” a resource that the brain builds throughout life and that can reduce the impact of cognitive decline associated with age. Cognitive reserve is the brain's ability to adapt and reorganize, maintaining functionality despite neurodegenerative diseases or aging.
According to studies, there are three key pillars to maintain and strengthen this reserve: physical activity, intellectual stimulation, and social relationships. “What is good for the heart is good for the brain,” explains Rieznik, emphasizing that physical exercise and a healthy diet help protect the brain. Intellectual stimulation, through learning new skills or activities that require mental effort, is crucial. This is because, according to neuroscience, learning is not additive but exponential: each new knowledge enhances previous knowledge and strengthens overall understanding. Finally, emotional bonds are essential; loneliness, on the other hand, is one of the greatest risk factors for cognitive decline.
Learning as a tool for intellectual growth and mental health
One of the most effective ways to preserve mental health is to maintain a constant interest in learning. According to Rieznik, “learning is not additive, it is multiplicative.” This idea is based on the concept of “compound interest” in learning, which suggests that each new knowledge interacts with and expands upon previous knowledge, forming deeper and more complex connections. Therefore, it is common to observe that people with years of experience and knowledge have a greater capacity to process new information and find solutions to complex problems.
Neuroscience explains that intelligence consists of two aspects: fluid intelligence and crystallized intelligence. Fluid intelligence, related to working memory and rapid information processing, tends to decline with age, although it can be maintained with physical exercise and intellectual stimulation. In contrast, crystallized intelligence, which is the ability to relate previous knowledge, tends to increase throughout life. This intelligence allows older individuals to have a broader strategic vision and apply past experiences to new situations.
Experimentation in neuroscience: self-deception in healthy individuals
To better understand how self-deception works in individuals without brain damage, researchers in Argentina, led by Rieznik, replicated an experimental study developed in Sweden in 2005. In this experiment, participants were asked to choose between two photographs, but then the photos were swapped without their knowledge. When questioned about their choice, they justified the decision based on the photograph they had not chosen. This phenomenon was also observed in experiments related to political opinions, where participants explained decisions they never made but believed they had made.
This type of self-deception evidences the existence of the interpreter: a mechanism that needs to make sense of our decisions, even when the original decision was not made consciously. In conducting these experiments, it was observed that individuals who justified a real decision tended to show more confidence than those who justified a altered decision. This finding, known as “unconscious detection of self-deception,” suggests that our brain can sense when it is self-deceiving, even if it is not always conscious of it.
The role of metacognition in self-criticism and personal development
Metacognition, or the ability to think about our own mental processes, plays a fundamental role in recognizing self-deception. According to Rieznik, “confidence is a good indicator of what metacognition is.” This means that when we feel doubts about a decision or a justification, it is possible that our brain is unconsciously detecting a self-deception. This phenomenon is also related to self-criticism, a skill that allows us to correct ourselves and improve the accuracy of our decisions.
Metacognition is also an important tool in the practice of meditation, as it allows individuals to identify and correct thought patterns that may be unrealistic or self-deceptive. Neuroscience is investigating how this type of self-criticism and self-regulation can improve overall well-being and mental health throughout life.