When a Christian athlete faces fear OR has an outburst of aggression, they have been taught that it comes from the “Lizard Brain.” Some will try to defeat their lizard brain, while others will blame the outburst of emotion on the so-called lizard brain. However, there is one major problem with this, and a big reason that Christian athletes need to stop blaming the Lizard Brain. 

The Lizard Brain Myth

It comes from an outdated Triune Brain Theory, proposed by neuroscientist Paul MacLean in the 1960s. This theory suggests that the human brain comprises three distinct layers: 

• Reptilian brain – the most primitive part, handling survival and instinctual behaviors.
• Paleomammalian brain (limbic system) – responsible for emotions.
• Neomammalian brain (neocortex) – enabling higher cognition and reasoning.

The problem is that the Triune Brain theory is a myth, not grounded in science or faith. As stated by modern-day leading neuroscientist Dr. Lisa Feldman Barrett, “one of the most successful and widespread errors in all of science.”

How The Brain Actually Functions

In reality, modern science shows the brain operates as a highly interconnected network, with various regions working together to process information and generate behavior (learn more here). The amygdala, often associated with the “lizard brain,” plays a crucial role in detecting and responding to threats. However, it does not function in isolation; it communicates with other brain areas, including the prefrontal cortex, which is involved in higher-order functions like reasoning and self-control.

Triune Brain Theory Is Based On a Hierarchical Model of Evolution

The lizard brain, stemming from the Triune Brain Theory, is based on the notion that, as humans, we started with the basic reptilian brain. Through evolution, we then added the limbic system, and then finally the neocortex. Do you see a problem here? 

“So God created man in his own image, in the image of God he created him; male and female he created them… And God saw everything that he had made, and behold, it was very good.” Genesis 1:27, 31

Humanity was made in God’s image and declared “very good.” This affirms that from the beginning, we were created whole, functional, and purposeful, not pieced together over time in layers like the triune brain model suggests. 

This does not mean the idea of evolution does not exist, as stated by Pope John Paul II in his address to the Pontifical Academy of Sciences, “evolution is more than a hypothesis.” However, we don’t just “add new parts” because we were created whole. Rather, the parts we were already created with develop to function at higher capacities to meet environmental demands.

If the Lizard Brain Were Not A Debunked Myth, It Still Wouldn’t Make Sense

At this point, we know the Triune Brain Theory is inaccurate—but even if it weren’t, the popular term “lizard brain” would still be misused. The Triune Brain model proposes three layers:

• The reptilian brain (basic survival functions like heart rate and breathing)
• The mammalian brain or limbic system (emotions)
• The neocortex (higher reasoning and emotional processing).

A lizard is, of course, a reptile, not a mammal—yet the term “lizard brain” is often used to describe emotional reactions. According to the outdated Triune Brain model, emotions arise from the mammalian brain, not the reptilian one. So the phrase “lizard brain” is a mislabel for an emotion that the theory itself attributes to a different brain region.

Learn more about Emotional Resiliency Here

In short, the term “lizard brain” inaccurately describes brain function based on an already debunked theory, making it doubly misleading.

Why Christian Athletes Must Stop Blaming the Lizard Brain

So when a Christian athlete experiences fear or anger, it’s not a “lizard brain” taking over. It’s a whole brain, created by God, responding to a challenge, and capable of choosing a faithful response.

Blaming a mythical part of the brain removes responsibility and ignores the spiritual tools God has already given us:

• The Holy Spirit, who produces self-control (Galatians 5:22-23)
• The renewed mind, which transforms how we think and act (Romans 12:2)
• The practice of self-agency, which starts with a pause between emotion and response

It is not appropriate or accurate for a Christian athlete to fall into the temptation of an emotional outburst and then blame it on a mythical theory that is neither grounded in science OR faith. God did create us with emotions; he also created us with the ability to respond vs react, a quick pause to allow a response vs reaction is rooted in the first pillar of hope: self-agency. Learn more in our top-selling book Hope Not Nope.

FAQ

1. What is the “Lizard Brain,” and where did it come from?
The “Lizard Brain” idea comes from the outdated Triune Brain Theory proposed in the 1960s by Paul MacLean. It claimed that the human brain evolved in three layers — reptilian, mammalian, and neocortex. Modern neuroscience has since debunked this model, showing that the brain functions as one interconnected system rather than separate parts.

2. Why is the Lizard Brain concept unbiblical and unscientific?
The Triune Brain Theory not only lacks scientific validity but also contradicts the biblical truth that humans were created whole and good in God’s image (Genesis 1:27, 31). We were not built in evolutionary “layers” but created with complete and purposeful design. The model reflects flawed science and misrepresents God’s creative intent.

3. How should Christian athletes view emotions like fear or anger?
Fear and anger are not signs of a “lizard brain” taking over—they are natural emotional responses processed by the whole brain. God designed humans with both emotion and reason, empowered by the Holy Spirit to respond faithfully. Practicing self-agency, pausing before reacting, and relying on God’s Spirit allows athletes to reflect His character even under pressure.

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Author: 

Dr. Dillon Caswell, PT, DPT, SCS

Doctor of Physical Therapy | Board Certified Sports Specialist

Hope Evangelist | Top-Selling Author & Speaker | Human Performance Expert