Dr. Hanscom's Blog MUST READ: threat physiology explained

This is from Dr David Hanscom's weekly newsletter. The full article is here: https://backincontrol.com/humans-wake-up-get-our-thinking-brains-online (Humans - WAKE UP! Get Our Thinking Brains Online - Back in Control)


Humans – WAKE UP! Get Our Thinking Brains Online

>>> Our lower brains are taking the human species down

KEY POINTS

Why do humans often not practice what they preach or believe?.
Abstract thinking and judgment don’t function during chaos.
We cannot solve humanity’s problems without clear and creative thinking.
Learning the skills to regulate our physiology is critical to our survival.
One thing that distinguishes human beings is their capacity for proactive, prolonged aggression, a human characteristic that results from the complex consciousness created by language.1 Since threats in the form of thoughts and concepts are perceived as concretely as physical threats, many threats are physically acted on.2 Many aggressive human behaviours are based on cognitive distortions, stories people make up about themselves and others. One of the most damaging ones is labeling others as “less than.” The physiological effects of threat on the brain compound the problem.

Your Brain Offline

Humans are a reactive and angry species compared to other mammals. They become enraged when necessary to optimize survival, and then they lie down and take a nap. Facing adversity is inevitable, but we not only make it up, but also hold onto it with complex language.

Imagine this: You’re in a heated argument with a friend. Your heart races, your face flushes, and suddenly, you say something you instantly regret. Sound familiar? In that moment, your thinking brain went offline. Blood flow is reduced, and activity is less intense. You cannot access your better judgment, and why are terrible deeds done?

Our ancient ancestors relied on their fight-or-flight response to survive predators and other threats. When a saber-toothed tiger appeared, their bodies flooded with adrenaline, shutting down complex thought so they could react instantly. This survival mechanism saved lives.

But here’s the problem: your brain can’t distinguish between a tiger and a tense conversation with your teacher. That looming deadline? Your brain processes it like a life-threatening danger. That argument on social media? Same response. Your body enters survival mode in response to both perceived and real threats.

The Human Survival Paradox

This is our paradox: the same brain that gave us language, creativity, and the ability to build societies also reacts to everyday stress like we’re fighting for our lives. When we feel threatened—whether by an actual danger or just the stress of an upcoming test—anxiety kicks in. And when we can’t find a solution, that anxiety transforms into anger.

That anger feels powerful for a moment. It gives you a rush, a feeling of control. But it’s an illusion. In reality, your thinking brain (the prefrontal cortex) has shut down, and you’re operating on pure emotion and instinct.

Your Brain on Stress

Here’s what happens physiologically: your brain requires massive energy – about 20% of your body’s energy goes to your brain, compared to just 4-8% in other mammals. When you’re stressed, blood flow shifts from your prefrontal cortex (your rational thinking center) to parts of the brain focused on survival.

Think about a basketball player who misses a critical shot and then plays worse for the rest of the game. They didn’t suddenly lose their skill. Their brain got stuck in survival mode, making accessing the complex skills they’ve practiced thousands of times almost impossible.

The same happens when you bomb a test you studied for or freeze during a presentation. It’s not that you don’t know the material—your brain can’t access that information when it’s in threat mode

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