T Nation

Do We Have Three Brains?


"The neurologist Paul MacLean has proposed that our skull holds not one brain, but three, each representing a distinct evolutionary stratum that has formed upon the older layer before it, like an archaeological site. He calls it the "triune brain." MacLean, now the director of the Laboratory of Brain Evolution and Behaviour in Poolesville, Maryland, says that three brains operate like "three interconnected biological computers, [each] with its own special intelligence, its own subjectivity, its own sense of time and space and its own memory".

He refers to these three brains as the neocortex or neo-mammalian brain, the limbic or paleo-mammalian system, and the reptilian brain, the brainstem and cerebellum (see above diagram). Each of the three brains is connected by nerves to the other two, but each seems to operate as its own brain system with distinct capacities.

This hypothesis has become a very influential paradigm, which has forced a rethink of how the brain functions. It had previously been assumed that the highest level of the brain, the neocortex, dominates the other, lower levels. MacLean has shown that this is not the case, and that the physically lower limbic system, which rules emotions, can hijack the higher mental functions when it needs to."



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Lol @ that. We divided human brain into those three pieces in elementary school.


Nice one!


My reptilian brain rules.


Well I'm glad I'm not the only one!


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I has 1 brain and its in my pants. Giggity!


Yeah. I picked up a minor in psych and this is hardly groundbreaking.

Oh, wait. What's that you say? Headhunter started this thread? THIS IS BULLSHIT!


Not groundbreaking? Screw you!

From the web site: "page first uploaded 19 May 1999"


This model is actually very useful for overcoming one's self limiting beliefs. Each "brain" communicates differently and independently of the other two. If you read enough about evolutionary psychology, you will see many theories that explain our "complex" behavior!