Biology is a science that can explain all human actions. All factors that direct our deeds are subject to interpretation.

The triune brain model explains the overall functioning of the human brain. In the 1960s, American physician and neurobiologist Paul MacLean created this model based on his research. According to his findings, the human brain consists of three layers.

The first layer is the reptilian complex or basal ganglia. Its name comes from the fact that the inner core of the human brain resembles the functions inherited from reptiles. It happened when mammals evolved from them approximately 300 million years ago. This layer controls the body's automatic functions, including body temperature, respiration, and heartbeat.

The second part is the emotional center. It is also known as the paleo-mammalian brain, or the limbic system. This part controls a person's emotions, social connections, and upbringing. Not only humans have this layer of the brain. For example, our four-legged friends, dogs, also have an emotional brain. That's why they can display their joy or sadness, and we can understand them.

The third part is the neocortex. It controls abstract thinking, memory, mathematics, language, planning, etc. When comparing the human neocortex with, for example, the one of primates, it is the larger and more developed.

The triune brain model isn’t all-encompassing for understanding how the human brain works. The brain's structure is incredibly complex, and dividing it into these three parts shows us a simplified model. However, according to studies, the human brain evolved in this sequence: primitive survival instincts, emotions, and abstract thoughts.