ALPHABETICAL BRAIN VOCABULARY Flash Card #78 - Details WHAT IS THE "TRIUNE BRAIN THEORY" EXPLANATION OF EVOLUTION AND WHY IS IT SO IMPORTANT? According to the TRIUNE BRAIN THEORY, primitive prehuman brains evolved biologically in three stages into modern human brains over many millions of years. The ancient brains of animals progressed from the primitive REPTILIAN COMPLEX (the first stage of the evolutionary brain), which became our modern BRAINSTEM and CEREBELLUM to the MAMMALIAN COMPLEX (the second stage of the evolutionary brain), which evolved in mammals with their distinct protective mothering styles of behavior, into the modern LIMBIC SYSTEM of human brains, and then, finally, from the NEOCORTEX BRAIN (the third stage of the evolutionary brain), which evolved into the CEREBRUM with its uniquely human "cerebral cortex" that gives human beings the ability to think and imagine alternative perspectives! This means that it took a three-stage process to make possible our unmatched human traits of self-awareness and free will as human brains evolved from simple ancient primitive prehuman brains over millions of years into complex modern brains. The Triune Brain Theory was an outstanding discovery in its original form when it was first proposed in the late 1940s and which was later described in more detail during the early 1960s. Even today, more than 50 years later, it is still very relevant even though more is now known about the incredibly intricate interactions of structures and functions in our brains. The "feedback functions" and the dynamic overlapping "competitively interactive" systems of the different major parts of human brains operate at both the conscious and unconscious levels. Because of its simplicity and its common sense rational explanation of evolutionary progress in the development of the wonderful structures and functions of human brains, the Triune Brain Theory remains an essential idea for an up-to-date modern understanding of how human brains evolved and how they work, whether healthy or not. Now that we know more detailed factual brain ideas, the power of this theory is not diluted by brain research. More intriguing details are being learned on a daily basis as the intricately complex microscopic mental processes are being integrated into the current understanding of how human brains work at the molecular level. Since Paul McLean developed the Triune Brain Theory explanation of human brain developoment in the early 1960s and Carl Sagan popularized it, its basic ideas remain relevant today. Return to #78: TRIUNE BRAIN THEORY or BRAIN FACTS MATRIX