“We´´´´ re thieves, we´ re rats. We know when to fight and when to run.”
Red Queen, by Victoria Aveyard
Fighting – real physical combat between at least two people with the intention to inflict potentially deadly harm – is and has been an integral part of human history, nature, and culture. While warriors and their craft have been revered in the past, fighting today is morally and legally restricted in most forms. We professionalized fighting by creating the profession of the soldier, who is allowed to fight and kill legally. The only legal way for a non-soldier to fight is to be forced to fight in self-defense. Real fighting is very different from training martial arts with friends in a relaxed atmosphere. A real fight – with the prospect of being harmed or even killed – will trigger a cascade of ancient reactions in our bodies – preserved by evolution over millions of years – that we share with most of our animal cousins. If we do not prepare for these natural reactions, much of the martial arts training will be for naught, it will not be available in a real self-defense situation and our primal instincts will take over and rule our behavior. In this blog piece, I will explore the neurobiology of fighting, i.e. how our bodies trigger a danger response and how we thus react to danger instinctively. (In a follow-up blog post, I will infer from this how we can try to make our martial arts training more realistic to account for these reactions. This will make us better prepared for a real fight when we have to defend ourselves.)
Fight or Flight – The Classic Paradigm
Many people have probably heard about the “fight or flight” paradigm. This model of how we react to danger to our physical well-being was proposed by US-American physicist and physiologist Walter Bradford Cannon in 1915 based on his own research 1. Essentially, the paradigm states that animals (and thus humans) will have a general response to a perceived threat which will always occur in the same way. There will be physiological and biochemical changes in the body to ensure maximal physical power and focus to either fight or to run away from the perceived threat.
To understand the paradigm in more detail we need to understand first a few biochemical and physiological processes that happen in these situations. If we need a quick response to something that happens around us and affects us (called a stimulus), we face a natural problem. Our main computing unit, our central nervous system (brain and spinal cord), which computes from sensory inputs targeted motor outputs, is pretty far away from those organs that can provide the physical response, namely our muscles and other organs. Here, there are two ways of how our brain can communicate with the rest of the body to ensure timely and fitting responses to stimuli. On one hand, we have nerves that provide fine-tuned information to our organs and muscles for specific tasks. And on the other hand, some organs can release hormones. These are biochemical compounds that are released into the bloodstream and thus reach all organs within a short amount of time. Albeit being slower than a specific nerve response, hormones have the advantage that they can regulate the state of the whole body once released and distributed via the bloodstream.
To summarize: To ensure a proper reaction to danger, we can utilize a nervous response and a hormonal response. Let´ s have a look at both of them.
The Nervous Response: The Sympathetic System
You are probably aware of the fact that there are certain bodily functions that you have no or very limited control over. You can´ t tell your stomach not to digest your lunch, but you could – if you wanted – keep your both fists clenched the whole day. These bodily functions outside of conscious control are regulated by the so-called autonomic nervous system. In essence, our whole body, all organs, are innervated by a fine web of nerves belonging to two main parts of the autonomic nervous system which are called the sympathetic and parasympathetic systems. Both systems are usually in balance to ensure what is called homeostasis which in turn is a fancy word for balance and means in this context to keep all physiological parameters within normal conditions. When, however, the fight or flight response needs to kick in, then the sympathetic nervous system is strongly activated (The parasympathetic nervous system, on the other hand, is responsible for the exact opposite, which is often called the “rest and digest” response). As stated before, however, we also need a hormonal actor, so let´ s look at who that is.
The Hormonal Response: Adrenaline
Next to our kidneys are small organs called the adrenal glands. Adrenal means in latin simply “next to the kidneys”. And one of their main functions is to release adrenaline2. This hormone which most people know plays a crucial part in the fight-and-flight response. Almost all tissues in the body have on the surface of their cells special proteins that fit to adrenaline like a lock to a key3 and will trigger specific danger/stress-related responses. How is a timely release of adrenaline ensured? As we have explored in the last section, if we want to react in the fastest way possible to make a remote organ to fulfill a specific task, we need a nervous response. So, the main way to release adrenaline is by activation through nerve fibers of the sympathetic nervous system.
Fight-or-Flight – Physiological responses
In reality, how the fight-or-flight response is triggered, is much more complex as described above, but keeping in mind that the main actors are the sympathetic nervous system and adrenaline is definitely sufficient when interpreting its actions in terms of a martial arts perspective.4
So, what happens actually in the body, when this response is triggered? A plethora of actions can be observed, I will only summarize those with relevance to fighting5:
- Acceleration of heart and lung function (increased heart rate, blood pressure and ventilation)
- Dilation of blood vessels in muscles (better flow of nutrition and disposal of metabolic waste)
- Constriction of blood vessels parts of the body not related to muscles and physical action
- Liberation of metabolic energy sources (particularly fat and glycogen from the liver) for muscular action
- Inhibition of the lacrimal gland (responsible for tear production) and salivation
- Relaxation of bladder
- Auditory exclusion (loss of hearing)
- Tunnel vision (loss of peripheral vision)
- Dilation of the pupil (mydriasis)
- Shaking, loss of fine-tuned movements and increased muscle tension
- Increase of aggression and loss of rational thinking (RAGE system)
In essence, what we become is a shaking bundle of rage full of energy, wanting to make big and strong movements, totally focused on the perceived danger with tunnel vision and loss of hearing, ready to either destroy or flee, and we might pee ourselves during the process. Something to look forward to…
Importantly, however, the loss of rational thinking means that the appropriate reaction will not be chosen rationally, but instinctively. The total opposite of what we are usually taught in martial arts training! But we will come back to that later.
The biochemical and physiological processes that lead to the fight-or-flight response are well understood and established today. The shortcomings of this model are not on the side of biology, but rather on the side of the number of potential responses to the physiological changes. So let´ s add some Fs to the response!
Fight, Flight, Freeze and Fawn – The Extended 4F Paradigm
Maybe you have been reading so far and were already thinking, yes, yes, this is very interesting, but I have watched a lot of discovery channel and I often see animals behaving very differently. They are neither fleeing or fighting, but rather just stand still and do not react at all!
And you are absolutely correct. When actually observing animals (and thus humans) we have found since the discoveries of Cannon in 1915 that we instinctively have a broader range of reactions to danger than just fighting and fleeing. Freezing – what I have described above – and fawning can be added to come up with a 4F model of reaction to danger. This model is also popular in the field of PTSD therapy, where PTSD can be seen as a state of continuous activation of the danger response.6.
Freeze
Freezing is the reaction where we maintain complete stillness while having a high muscle tone at the same time7. This behavior can be a highly appropriate reaction to danger. Many predators are triggered by running prey and their perception is often tailored to find moving targets but not those standing still. This is especially true when considering that a predator is also using adrenaline for maximum physical power and will also suffer from tunnel vision. Also in humans, this response is known. There are often reports stating that people survived shooting sprees by playing dead.
Fawn
Fawning is a bit harder to grasp. It is defined as to “give a servile display of exaggerated flattery or affection, typically in order to gain favor”8. In the context of danger, it means to defer to the attacker in a way as to acknowledge the dominance of the attacker to avoid physical harm. This refers to a very atavistic ritual part of fighting which is often seen in animals and humans as well. From an evolutionary perspective, it is not the best to always have a full-blown fight, even if you are the stronger one! Wounds can lead to death through infection even when a fight was won. Deferring to the dominant person without getting physical will lead to the same outcome and none of the combatants is harmed.
Freeze, Fight, Flight, Fright, Fawn and Faint – Please bear with me, the 6F paradigm is the last, I promise…
Is the 4F paradigm good? Yes. Is it sufficient? No.
It was – in my opinion rightfully pointed out – that freeze is not a good name for the before mentioned reaction as a _short_ freeze almost always happens as part of the first reaction to danger when we are startled. Thus, every danger response starts with a short freeze. What was called freeze before will now be called fright. So we would end up with:
Freeze, Fight, Flight, Fright, and Fawn. BUT we will add another reaction that is interestingly unique to humans and does not need much explanation: Faint.9.
So, our final model is the 6F model to danger:
First, we freeze shortly, and then we will either fight, run away, do absolutely nothing, try to avoid fighting by showing deference or we will faint.
But which one of these reactions will happen?
And how is it related to martial arts training?
This I will explore in the upcoming blog post: “The Neurobiology of Fighting – Part II: How to tame the Autonomic Beast”.
Appendix
Here is the promised appendix. So, in the end, things are a bit more complex and I would like to touch upon this as recently there was a viral – pretty bad – news headline going around that “our bones help us fighting”10.
So, let´ s explore in a bit more detail, how the danger response is triggered. The important concept here is the one of the equilibrium that I have already mentioned. This means that the sympathetic system and the parasympathetic system are in balance. Imagine two – equally strong – opponents pushing against each other with the same strength. Nothing will happen. Now, if you make one the first person stronger, then naturally this person would push the other one away. So, to elicit a danger response, – as outlined in detail above – sympathetic reactions are triggered in the body through sympathetic nerve fibers and adrenaline, making the sympathetic system being stronger than the parasympathetic one.
So far, so simple. However, what would make the shove even stronger? Exactly, if we not only made the first person stronger but at the same time the second person weaker. And indeed, this can be done by weakening the parasympathetic system! The main finding of the related scientific article[/efn_note]https://www.sciencedirect.com/science/article/abs/pii/S1550413119304413?via%3Dihub[/efn_note] was that the release of osteocalcin, a hormone produced in the bones, leads to a weakening of the parasympathetic system thus tipping the balance also in favor of a danger response.
I would claim that it is not more bizarre to use a hormone produced in the bones (osteocalcin) than to use a hormone produced in the adrenal glands (adrenalin) to elicit a danger response.
Also, this makes much sense from an evolutionary perspective. To have a danger response was crucial for survival. So, having two systems working together ensured that one can compensate for the other. And indeed, in humans and animals without adrenal glands still danger responses could be elicited. The discovery of the osteocalcin effect can explain that.
So, definitely interesting findings, but nothing weird or bizarre in my opinion!
