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Be aware, beware of the reptilian brain

THE senseless killing last week by a policeman of a mother and her son in the course of a neighborhood squabble, and in front of the policeman’s teenage daughter, should remind us again of that reality most of us do not know or are oblivious over because we haven’t been educated about it or because of our religious beliefs.

The reptilian brain, rampaging in Tarlac and in Minneapolis. SCREEN GRABS 

This is the fact that we humans are not magical creatures created by some deity in his image: we are the end result of 3.7 billion years of evolution. Our brains were not manufactured by some intelligent designer but evolved through time, its prime directive being, as it were, to survive.

One thesis proposed back in the 1960s mainly by neuroscientist Paul MacLean became popular because of its simplicity: we have a “triune brain,” that is, what we think of as our brain consists of three brains: the reptilian complex, the paleo-mammalian complex (limbic system) and the neocortex. These structures were sequentially added to the forebrain in the course of evolution.

What we think of as our brain which allows us to philosophize, socialize and be civilized in general is the neocortex, those two large hemispheres which figure in the usual depiction of the human brain. It was the last to develop through evolution, appearing first in primates. The second brain is the limbic brain which first emerged in mammals, which is largely responsible for our emotions.

The oldest is the smallest, the reptilian brain consist of its stem and its basal ganglia, which is an automatic system, called as such as it was believed to dominate reptiles’ brains. It had ensured creatures’ survival, mainly through the fight or flight response. If our ancestors had to think first if a saber-toothed tiger in front of it could kill him, our species would have become extinct long ago. The reptilian brain orders the creature to either fight or flee.

More recent neuroscientists have linked the function of the reptilian brain to the limbic system, especially to those tiny almond-shaped structures called the amygdalae where emotions are generated — believe it or not, through certain kinds of chemicals released — in order to make the survival system more efficient. That is, the reptilian brain commands the creature’s flight, the amydala provides the sense of fear to emphasize, yes, you have to flee, like now.

The reptilian brain and amygdala complex interacting with the cerebral complex has evolved not just to ensure a human’s physical survival, but for the defense and survival of his ego, that complex construct in one’s mind that one believes is his very being, which you can call the ego, the self or even the soul.

The three brains. Linwit.us.


When that ego is threatened — even if only deflated — that reptilian brain springs to action, as if the human’s very existence is threatened.

If that brain is unchecked by the functions of the neocortex, it would lead to tragic consequences.

It was the reptilian brain that was let loose in Rolito Go’s mind when he shot and killed in 1986 a student over a mere traffic altercation — which in his mind threatened his social status. Thanks to cameras in cellphones, we witnessed that reptilian brain rampage in Minneapolis as a policeman choked the life out of an African American man through nine and a half minutes.

That the cop could slowly kill a man for that long is due to the physiology and chemistry of anger, as one account explains:

“As you become angry your body’s muscles tense up. Inside your brain, neurotransmitter chemicals known as catecholamines are released causing you to experience a burst of energy lasting up to several minutes. This burst of energy is behind the common angry desire to take immediate protective action. At the same time your heart rate accelerates, your blood pressure rises and your rate of breathing increases. Your face may flush as increased blood flow enters your limbs and extremities in preparation for physical action. Your attention narrows and becomes locked onto the target of your anger. Soon you can pay attention to nothing else. In quick succession, additional brain neurotransmitters and hormones (among them adrenaline and noradrenaline) are released.”


Filipinos have terms to describe that process, two of the most popular being: “Nagdilim ang pagiisip ko; dinapuan siya ng demonyo.” I don’t know why Filipino movies with all their de rigueur shouting and crying depict letting the reptilian brain loose seem normal and even desirable.

We have all of course experienced the reptilian brain take over our mind, making us do something we regret our whole lives, but fortunately for us what we did wasn’t so terrible enough to make our remaining lives miserable. That wasn’t the case for that cop Jonel Nuezca in the Tarlac killing last week.

That Tarlac cop in the first 10 minutes seemed to be keeping his cool, restraining the young man by his waistband as policemen are trained to do so, waiting for barangay (village) officials. But in the short span of two seconds, his reptilian brain took over, shooting twice in the head two defenseless human beings.

Perhaps his reptilian brain interpreted the poor mother’s mocking of his being a policeman (after his daughter boasted that he is) as a threat to this ego or maybe he wanted to bloat his alpha male status before his daughter. We don’t know, the reptilian brain doesn’t think the way the neocortex does. The reptilian brain doesn’t think of consequences, only the now.

Our modern civilization has struggled to keep that reptilian brain under control. It cannot be destroyed of course as it also operates most of our biological systems necessary for life — breathing, the regulation of the heart, the release of the necessary chemicals needed by the body. We couldn’t exist for a minute if the reptilian brain dies.


Religion, other than its ancient function of helping monarchs rule, became a widespread and powerful institution because of its huge role in controlling the reptilian brain, successfully inculcating the fear that letting it loose for a moment would result in one’s suffering for eternity. It is not coincidental that the Virgin Mary and less often Christ himself are depicted standing over a snake.

The state and its systems of justice have been developed to remind people to control their reptilian brains, or else. There lies the dilemma: the state’s police is intended to check reptilian brains from rampaging in society. But policemen also have reptilian brains that could get out of control, whether in Tarlac or Minneapolis.

Would it be better if policemen, as in the United Kingdom and Japan, were armed only with batons?

For the sake of our loved ones and yourself, be aware, beware of the reptilian brain in you. At the very least take a deep breath, count to 10 or even to a hundred. Or just go away.

Email: tiglao.manilatimes@gmail.com
Facebook: Rigoberto Tiglao
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This Post Has 2 Comments

  1. Hunter

    I still hope people never lose his faith in humanity.

  2. Hunter Thompson

    That is why human beings are no special. Carlin siad it well: the human specie are the worst creatures God had ever created. Carlin emphasized:

    “Most animals, when fighting one of their own, will show aggressive behavior, but very little hostility or intention to harm. And when the outcome of the struggle is inevitable, the losing animal will signal its defeat by exposing its most vunerable part to the victor, affording it the opportunity to finish the kill. The victor then walks away without inflicting further harm. These are the creatures we feel superior to.”

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