Have you ever heard the term "lizard brain" used to explain why you might be struggling with focus, organisation, or emotional regulation? It's a popular idea, often found in self-help books and even some psychology resources. The idea suggests that deep inside your brain, there's a primitive "reptilian" part that drives your impulses and makes it difficult to control your behaviour. This concept proposes that the human brain has three layers: the oldest reptilian brain that controls basic functions, the limbic system for emotions, and the cerebral cortex for language and reason. You might hear people say that your "lizard brain" is responsible for your "fight or flight" responses, or for making irrational decisions.

But here's the thing: the "lizard brain" is a myth. Contemporary neuroscience and evolutionary biology have widely discredited this idea. It was first proposed by neuroscientist Paul MacLean in the 1960s, but it's now considered outdated and not based on current scientific understanding.

The Problems with the "Lizard Brain" Concept

• Evolution is not linear: The idea of the brain developing in layers, from reptiles to mammals to humans, is incorrect. Mammals did not evolve from reptiles. Instead, both share a common ancestor. Complex nervous systems evolved independently in different animal lineages.
• The cortex is not unique to mammals: Reptiles, fish and birds also have a cerebral cortex.
• Brains don't develop in layers: The idea that more complex layers are added on top of simpler ones as species evolved is wrong.

Emotions are Constructed, Not Pre-wired

The idea of the "lizard brain" suggests that emotions are hard-wired and automatic. However, current neuroscience shows that emotions are constructed. Emotions are not pre-programmed into the brain. Rather, they are built from various ingredients, such as body sensations, the situation, memories and experiences, language, and social context.

There isn't a hard-wired "fear circuit" in the brain. The brain has threat-detection circuits, but learning, memory, language and culture are also ingredients that combine to create feelings such as fear or anxiety.

What does this mean for ADHD?

• The "lizard brain" model suggests that human behaviour is driven primarily by fear, and that our "reptilian" brain overpowers calm and rational thought.
• This idea reduces the complexity of human emotions and removes your agency and ability to manage emotional experiences.
• When people believe that their behaviour is controlled by a primitive brain, it can be disempowering. It removes the possibility that you can have agency over your emotional and behavioral responses.

So what should we believe about our brains?

• Instead of viewing emotions as automatic reactions, recognise that you are the architect of your own experiences.
• Emotions are created using the ingredients of your body sensations, life experiences, expectations, and the situation you're in.
• You have the ability to consciously construct and regulate your emotional responses.
• By developing your emotional vocabulary and understanding the ingredients that make up your emotions, you can better understand and manage your responses. For example, a fast-beating heart doesn't always mean your brain has detected a threat, it might be because you are excited or exercising.
• You can learn to see fine distinctions in emotions, and become an expert namer and categoriser of them.
• Instead of talking about the "reptilian brain" we can focus on understanding what ingredients go into making our emotions.

Understanding that the "lizard brain" is a myth can be empowering. It means that your ADHD is not a sign of a primitive brain holding you back, but that you have the potential to construct your emotions and responses, and develop skills to manage your ADHD. By recognising that your emotions are constructed by various ingredients, you can develop a sense of agency over your thoughts, feelings, and actions. As a coach, I can help you to develop the skills, awareness and tools to become the architect of your emotional and behavioural responses.

Based on information from:

• Your Brain Is Not an Onion with a Tiny Reptile Inside by Joseph Cesario, David J. Johnson, and Heather L. Eisthen
• drsarahmckay.com