The Wise and the Wild: Mysteries of the Human’s Brain

Our brain is one mysterious organ. Yet, the basic concept of brain evolution helps us understand how it functions on a broad sense, and therefore deduce how we, humans, function on a broad sense. This concept, called the triune brain theory, suggests that the human brain comprises three main evolutionary layers: the reptilian brain - for survival instincts, the limbic system - for emotions and memory, and the neocortex - for advanced cognitive functions. To make things simpler, we’ll use the terms “reptilian brain”, “mammalian brain” and “thinking brain”, respectively. We, humans, have these three parts in us, and only one of them is unique to us as species - can you guess which? Yes, it’s the thinking brain, which gave us the catchy name “homo-sapiens”, which roughly translates to “wise human”.

This so-called “wisdom”, which applies to our intellectual capabilities, was a key element in science and religion alike. In science, because of the famous quote of Descartes - “I think, therefore I am”, which perpetuated hundreds of years of split between the mind and the body in the modern science, and in religion (mostly the three big ones), because of notions like “humans should tame their animalistic nature”, “humans should overpower their animalistic instincts with will power”, and similar ideas.

The triune brain model, helps us to understand particularly the universal “fight-or-flight” response, which we share with the entire animal kingdom. The reptilian brain contributes to the "fight-or-flight" response by initiating rapid, instinctual reactions to immediate threats. While it doesn't directly control the physiological changes associated with the response (like increased heart rate or adrenaline release), it can trigger initial reflexive behaviors, such as jumping away from a sudden loud noise or instinctively ducking to avoid a fast-moving object. These initial reactions are then further modulated and amplified by the mammalian brain (particularly the amygdala), which is responsible for the more complex emotional and physiological aspects of the "fight-or-flight" response.

The "fight-or-flight" is activated in response to perceived threats or stressors in the environment. It is an evolutionary adaptation that prepares the body to either confront the threat (fight) or escape from it (flight). The activation of this response triggers a cascade of physiological changes to help the individual deal with the perceived danger.

The "fight-or-flight" response can be triggered by various stimuli, including:

  • Physical Threats: Direct physical threats such as an attack by a predator or a dangerous object approaching suddenly.

  • Psychological Stress: Stressful situations such as public speaking, financial worries, relationship conflicts, or work pressure can also trigger the "fight-or-flight" response.

  • Emotional Threats: Strong emotions like fear, anger, or intense anxiety can activate the response, especially if they are perceived as threatening to one's well-being.

  • Perceived Danger: Even situations that are not objectively dangerous but are perceived as threatening can elicit the response. For example, a person feeling threatened by a loud noise in a dark alley, even if there is no actual danger present.

The activation of the "fight-or-flight" response involves complex interactions between the brain, particularly the amygdala and other parts of the limbic system, and the body's autonomic nervous system. This leads to physiological changes such as increased heart rate, rapid breathing, heightened alertness, dilation of pupils, and redirection of blood flow to muscles, all aimed at enhancing the body's ability to respond to the perceived threat effectively.

In today's society, many situations that trigger the "fight-or-flight" response are not life-threatening or physical in nature. For example, stress from work, interpersonal conflicts, traffic, deadlines or financial worries, can activate a similar stress response without the need for physical confrontation or fleeing. Some individuals may experience frequent or chronic activation of the "fight-or-flight" response due to ongoing stressors, anxiety disorders, trauma, or high-pressure environments. In such cases, the continuous activation of this response can have negative effects on physical and mental health, leading to issues like chronic stress, anxiety disorders, cardiovascular problems, and immune system dysfunction.

This frequent activation undermines our ability to think clearly, which means that in stressful situations our cognitive abilities might be severely impaired. Considering the fact that our modern life is stressful pretty much for all of us, it raises the question of are we really as rational as we think we are. The renowned book “thinking, fast and slow” (written by the Nobel prize winner, Daniel Kahneman), showed us that we are much less rational than we would like perceive ourselves. Further discussion of the fight-or-flight response would strengthen this claim even further.

So why are we called “the wise human”? Why not “the feeling human” or “the sensing human”? It seems that we should have been called “the sensing, feeling and thinking” human, to be true to our evolutionary origins and more accurate in our perception of ourselves.

What do you think? Or better ask, how do you feel about it? (we’re psychotherapists, after all...).

Posted in: April 1, 2024