The Three Brain Systems

Understanding how any device works allows us to troubleshoot and fix it when something goes wrong. The same goes for our brain—knowing its systems, their unique features, and how responsibilities are distributed helps us better understand ourselves and the nature of our behavior. This knowledge gives us a deeper level of self-awareness, more effective control over our actions, and the ability to achieve the results we want.

Knowing how the human brain functions shows us where it can be our ally and, surprisingly, where it might hold us back. By exploring how these systems interact, we gain insight into why many people struggle to achieve their dreams and how to avoid wasted effort. Let’s take a look inside our own minds and see how this “communal apartment” operates.

All people have a triune brain system, which includes the reticular (reptilian) brain, the emotional (limbic) brain, and the visual brain (cerebral cortex, neocortex).

1. The Reptilian Brain (R-Complex) – The Mammalian Brain

The reptilian brain is about 100 million years old and is the oldest part of our brain. It has a fundamental influence on our behavior and is responsible for the survival of the species and basic behaviors, such as:

• Instinct for reproduction
• Territorial defense
• Aggression
• Desire to possess and control everything
• Following patterns
• Imitation and deception
• Struggle for power and hierarchical structures
• Ritualistic behavior
• Minority control

This part of the brain is characterized by cold-blooded behavior, lack of empathy, and indifference to the consequences of our actions for others. In modern terms: “winner takes all,” “might makes right,” and “winners are never judged.” It’s no coincidence that we call a killer “cold-blooded,” and philosopher Niccolò Machiavelli advocated “cultivating the beast within.” The reptilian brain is often evident in the behavior of politicians and those in power.

Its functions are simple: “fight, flight, or freeze.” It’s essential for immediate reactions—first comes the reaction, then the reasoning. In this sense, it’s our “autopilot,” which we cannot consciously control. Its main job is to protect the body, always on guard for danger. As a result, it tends to see the world as full of threats and deception.

The reptilian brain perceives the world differently. It holds traces of our primitive “reptilian” fears, which children often display for no apparent reason as soon as they learn to speak. Perhaps it’s no accident that the “psss!” sound we use to call for silence or attention resembles the hissing of our reptilian ancestors. Our R-complex also operates in our dreams, where we still hear the footsteps of dinosaurs. We can’t bypass or ignore it, but evolution has created inhibitory centers in the temporal lobes to slow down excessive reptilian activity. During the day, the neocortex suppresses the R-complex, but during sleep, it can reactivate, causing us to experience primal fears—falling, being chased, or sexual experiences.

The reptilian brain is vital for survival in real danger. But if survival mode becomes your entire life, you become its prisoner. This part of the brain is also the primary target for external manipulation—constant fear of “not surviving” is instilled through news about crises, rising prices, wars, disasters, violence, and painful reforms. Remember: this kind of programming tries to “lock” you in your reptilian brain to make you easier to control. All they need from us is our fear.

Sometimes, it confuses imagined danger with real threats, taking control of your mind and body. In prehistoric times, it protected us well, but now it often slows down our personal growth until it’s sure we’re safe. You’ve probably experienced moments when your reptilian brain took over and you “overreacted” to a situation. In a way, our reptilian brain still performs the functions of ancient dinosaurs or our wild ancestors.

2. The Limbic System – The “Emotional Brain”

The limbic system is about 50 million years old, inherited from ancient mammals. It:

• Is responsible for individual survival, self-preservation, and self-defense
• Manages social behavior, maternal care, and upbringing
• Regulates internal organ functions, smell, instinctive behavior, emotions, memory, sleep, wakefulness, and more

This brain is 98% identical to that of our “lesser brothers”—animals. Maybe that’s why we love our pets so much? The emotional brain is the main generator of emotions, linking emotional and physical activity. Here, fear, joy, and mood changes are born. The limbic system is also affected by psychoactive substances. Malfunctions can cause unexplained outbursts of rage, fear, or sensitivity.

The emotional brain gives us the “life of feelings.” It’s important to know that it’s a “monotonous brain”—it loves comfort and routine, seeking safety and stability. For the emotional brain, safety means doing today what you did yesterday, and tomorrow what you do today. Working with the reptilian brain, it brings lessons from the past into the present and doesn’t think about the future. It links all memories as if events are happening now, so you relive feelings and emotions from past experiences.

The “gravity” of the emotional brain, in its desire to preserve what we already have, shows up as resistance to change, pulling us back into the so-called “comfort zone”—the status quo, as part of homeostasis. Any attempt to leave this zone is stressful for the emotional brain. Remember this concept—“comfort zone”—it’s crucial for understanding our behavior when we try to make changes.

You could say this is our “caring and protective parent.” It likes familiar things: “mom’s cooking,” everything that made you happy as a child, familiar surroundings, behaviors, and settings. Every decision you make passes through its filter: “Is this good for me? Is it safe for my family? Is there any threat?” If something seems threatening, you reject it. In other words, when the emotional brain makes decisions, it’s based on what’s close and familiar to you.

When you feel resistance to change, it means your emotional brain is in control. Its features include:

• Living in the present moment
• Auditory communication (using sounds and tones)
• Group orientation—its priority is the survival of the group, family, or clan
• Sees only “yes” or “no,” “good or bad,” “this or that”—no gray areas
• Associates with specific life moments—when we think about something, we take on a role and experience feelings

The emotional brain doesn’t distinguish between threats to our body and threats to our ego. That’s why we start defending ourselves without fully understanding the situation. When someone hurts our feelings, it releases adrenaline, increases blood flow to large muscles, and instantly focuses our thoughts on defending against the threat.

It’s important to know that before any transformational process can begin, the emotional brain must be convinced that the whole group, family, or clan will be safe. It always looks for similarities. For example, when meeting new people, it feels the safety of the “comfort zone” only when it sees that the new person is similar to you. This is its “friend or foe” function. Convincing it is the job of your rational mind.

“Everything you want is just outside your comfort zone,” says Robert Allen, co-author of “The One Minute Millionaire.”

The reptilian and emotional brain systems have coexisted for 50 million years and work together very well. That’s why it’s important to understand that these two tightly linked systems often take control of your mind and body. For the reptilian brain, threats are physical; for the emotional brain, they’re emotional—like losing love, fear of the unknown, or life changes. Your emotional brain may reject your efforts, for example, when you’re trying to lose weight. Instead of eating right, you find yourself unconsciously reaching for food. The emotional brain is to blame—it’s focused on the “now” and quickly acts on your current desires, immediately triggering your habits. Anyone who’s tried dieting knows: lose control for a moment, and extra calories are in your mouth.

So how do you overcome the “caring habits” of our oldest brain structures and achieve what you consciously want? You need to learn how to use the power of the visual brain.

3. The Visual Brain (Cerebral Cortex, Neocortex – Left and Right Hemispheres)

This is the rational mind—the youngest structure, about 1.5–2.5 million years old. It’s what we call reason and is responsible for:

• Thinking
• Reasoning
• Analytical ability
• Cognitive processes, and more

It has spatial thinking, creates visual images, focuses on the future, and analyzes it. With 16 trillion connecting neurons, it occupies most of the skull.

The human brain contains about 10¹³ synapses. A synapse is the contact point, or gap, between neurons. The number of possible states the brain can be in is 2 multiplied by itself ten trillion times. This unimaginably large number far exceeds the number of electrons and protons in the universe, which is less than 2 raised to the power of 1,000. If you tried to write out all the possible combinations (neural connections), it would take 75 years just to write the zeros! This gives us incredible flexibility of thought, enormous potential for envisioning the future, and a thirst for knowledge.

With this part of the brain, you can imagine anything you want! It’s also our “thought mixer” (about 60,000 thoughts per day!).

This brain can:

• Determine what actions you need to take
• Set goals and make plans
• Discuss your goals and dreams
• Inspire you and motivate short-term action
• Use logic to accept or reject ideas and goals

It’s important to remember that the conscious brain is not responsible for long-term actions. Today, neuroscience has proven that the conscious brain is responsible for only about 2% of our long-term goals. The remaining 98% is the domain of our subconscious.

Paul MacLean, the author of the triune brain model, said: “We must look at ourselves and the world through the eyes of three completely different personalities,” two of which are not equipped with speech. The human brain, according to MacLean, “is equivalent to three interconnected biological computers,” each with “its own mind, its own sense of time and space, its own memory, motor, and other functions.”

Emotion is energy generated by the subconscious. This energy matches the informational program of the emotion: fear produces the energy of fear, resentment produces the energy of resentment, and so on. This energy carries a specific program—either destructive or creative.

Feelings and emotions reflect our attitude toward an event or person. Emotions are immediate, animal-level reactions, while feelings are more a product of thought, experience, and reflection.

Emotions are our psychological reaction to events, accompanied by changes in breathing, pulse, gestures, and more.