Inertia

What is inertia?
IN BRIEF

Sometimes, in certain situations, autistic people may find it difficult to determine the best way to act or the correct response to give. In such cases, they might suddenly become unable to move or speak. This isn’t intentional, nor does it mean the person is confused. They understand what’s happening but are unable to act in the moment. Inertia occurs when an autistic person experiences overload, leading to a sense of confusion. The individual may seem unable to move—not because they physically can’t, but because they cannot decide what action to take. It can resemble one of the stress responses known as "fight, flight, or freeze," though it is not identical.

Inertia occurs when an autistic person experiences overload, leading to a sense of confusion. The individual may seem unable to move—not because they physically can’t, but because they cannot decide what action to take. It can resemble one of the stress responses known as “fight, flight, or freeze,” though it is not identical.

Inertia in social situations

Autistic people have their own unique ways of interpreting social interactions. Their communication style is often different from that of neurotypical individuals. Over time, some autistic people become skilled at understanding how allistic (non-autistic) people communicate.

To improve communication, many autistic individuals spend significant time preparing phrases and actions they can use in social settings. Often, when the moment comes, they hesitate between several options. If they cannot find a way to communicate that will achieve the desired outcome, they may enter a state of inertia—becoming unable to speak or move. This is even worse if they are aware of potential negative consequences for not finding the “correct” response, the one that is “normal” or “socially acceptable.”

Imagine needing to interact with a non-player character (NPC) in a video game to advance to the next level, knowing that every possible response leads to a “game over.” That scenario hardly motivates anyone to play.

Going further
EXECUTIVE DYSFUNCTION

Inertia is a form of executive dysfunction. Executive functions are complex brain processes that allow us to take appropriate actions in specific contexts and adapt to our environment. When someone enters a state of inertia, they are unable to perform the actions expected in the situation.

Important

A person experiencing inertia is not doing it on purpose. They cannot simply stop being in that state, and pressuring them to do so is harmful.

An autistic person in this state may feel intense stress if they are aware of negative consequences. However, even under stress, they remain acutely aware of their body—sometimes even more than usual. In a calm environment, surrounded by trusted individuals, this state can be experienced without stress. Reflecting on it later can even feel amusing!

Inertia without stress

An autistic person might enter a state of inertia because they cannot find a good solution to an everyday problem. For example: How can someone enter their house without getting the floor or their socks wet when covered in snow? If they remove their boots immediately, their socks will get wet, leaving unpleasant damp footprints everywhere. But if they keep their boots on, water will puddle all over the floor.

In such cases, while deciding between saving their socks or the floor, there might be a delay. Often, the snow will melt, wetting both the socks and the floor before any decision is made.

A similar phenomenon can occur in people with ADHD since this too is a form of executive dysfunction (as defined earlier). Inertia could be thought of as “executive dysfunction statue mode.” In cases of inertia, however, it always happens during moments of emotional and/or sensory overload.

Inertia or freezing?

Autistic people can also exhibit stress responses or reactions to trauma. All humans—and even many animals—share common stress responses. When faced with danger, one might fight, flee, or freeze. From the outside, inertia can look like freezing. In fact, many people describe it as “I froze.” However, freezing in response to danger often involves disconnecting from the body as a protective measure. Anyone who has experienced or is experiencing trauma can freeze and disconnect from their body.

In contrast, during inertia, people remain connected to their body. Their mind stays clear, and they continue to perceive their environment as usual. They simply cannot find the “right response” to proceed. A person who freezes due to trauma, however, might feel that reality becomes blurred, lose their usual sense of their body, or even feel as if they are outside of their body.

One day, I was in a room where several folded tables were leaning against the wall. Slowly, they began to slide down. All I had to do was place my hand in front of them to stop them. But as I watched the tables slide, I couldn’t decide what movement to make next or how to follow up once I placed my hand. So, unsure of what to do, I did nothing, and everything collapsed. The people around me didn’t understand my lack of reaction

Because autistic people do not perceive social information the same way as allistic individuals, it’s possible for them to “freeze” in a social situation that does not seem traumatic to others.

What if someone disconnects from their body?

If someone feels disconnected from their body, this is no longer inertia. When this happens, it’s important to seek help from a psychologist. Autistic people, like everyone else, can experience situations of abuse. However, they may find it harder to identify these situations, which increases their vulnerability to repeated abuse.

Important

Freezing is a signal from the body indicating it has detected danger.

As soon as movement is restored, it’s crucial to seek help from a psychologist, social worker, or psychotherapist. These professionals can help understand what’s happening and find solutions to ensure safety.

Catherine Bouchard-Tremblay

Science popularizer