The Reactive Brain: Always Anticipating the Worst

States of anxiety often occur when all you can see are problems and you just don't know what to do about them. Then, your brain tends to adopt a reactive approach. This kind of approach has very specific characteristics.
The Reactive Brain: Always Anticipating the Worst
Valeria Sabater

Written and verified by the psychologist Valeria Sabater.

Last update: 15 November, 2021

Your reactive brain orchestrates, facilitates, and activates your anxiety mechanisms. This way of thinking and processing information works by alerting you to anticipate risks that often don’t even exist. Indeed, this approach also makes you over-emotional, lack initiative, and be more impulsive and less reflective.

Viktor Frankl wisely pointed out that when you can’t change a situation that’s causing you pain or discomfort, what you can do is change your attitude towards the problem in order to reduce your suffering. However, if you have a reactive brain, you’re unable to carry out the mental engineering involved in this kind of strategy. Because to approach reality in this kind of way, you need a proactive brain.

Although the term “proactive” has tended to relate, in recent years, to the field of leadership, organization, and workplace psychology, in reality, the concept itself actually indicates health and psychological balance. In fact, what’s really positive is that it gives you the ability to move from reactivity to proactivity and you get a chance to manage adversity in your life.

The reactive brain.

The reactive brain: what is it?

The reactive brain’s related to a specific type of cognitive processing. Your reactive brain sees changes as threats and responds to stimuli by anticipating the worst possible results. That’s to say, your brain responds impulsively or anxiously. Indeed, neuroscientists have been trying to understand the neurological foundation of anxiety and what’s known as the hyperactive mind.

Studies such as those conducted in 2018 by Dr. Alexander Olsen, a professor in the Department of Psychology at the Norwegian University of Science and Technology, reveal interesting data that’s well worth looking at.

Thinking proactively or reactively: what’s the difference?

The human brain can process information, reason, and drive behavior based on two basic mechanisms. These are proactivity and hyperactivity.

  • The proactive system forms a part of your fluid intelligence. This type of intelligence refers to your ability to solve problems by using logic and identifying patterns. In effect, thinking more reflexively.
  • On the other hand, your reactive system’s more impulsive and needs to respond quickly to the stimuli of the environment. It does this because your response often originates from fear. This is your personal alarm system that activates the amygdala and makes you act before you think.

In reality, you use both forms of thinking. Your reactive system’s useful when you need to act regarding risks and threats in your environment. On the other hand, the proactive approach allows you to make better decisions and manage everyday stress more effectively.

However, problems arise if you only use the first approach, leaving your reactive brain to orchestrate almost every situation. Then, you’ll find yourself drifting into a constant state of anxiety.

The reactive brain and white matter

Dr. Alexander Olsen’s team conducted his study in collaboration with the University of Southern California at the Stevens Neuroimaging and Informatics Institute. Their goal was to see what mechanisms cultivate and shape the active brain. With MRIs, they saw that, when people think fluently and proactively, the white matter in the brain’s proactively activated.

On the other hand, those people who reasoned reactively had a lower density of white matter. This area actually consists of a wide and complex network of myelinated axons which are essential for the brain to communicate. Furthermore, this area’s the key connection between the left and right hemispheres of the brain.

In effect, when you become used to responding to your environment reactively, you’re in a state of constant hypervigilance. This means you only see threats, anticipate problems, and suffer stress. These states affect your brain considerably. In fact, they alter your brain to the point of disorganizing the white matter network within.

A couple jogging.

How do you change from a reactive brain to a proactive brain?

You can’t just switch off your reactive brain. This is because you can’t completely remove reactive reasoning from your mind. In fact, this way of processing is sometimes both useful and necessary. For instance, when you face threats or dangers in your environment.

However, the ideal situation would be that you only activate your reactive brain on certain occasions. Because leaving these particular situations aside, you only really need your proactive brain. This is because it’s your proactive brain that mediates your well-being by reducing your anxiety.  So how do you develop and activate your proactive brain?


  • Edward de Bono defined proactive thinking as the mechanism by which you simply let things happen. In effect, you become an active agent of your own reality.
  • You must control your emotions and impulses at all times.
  • You must develop a more thoughtful mindset and be open to new perspectives. Mental rigidity always leads to reactivity and fear.
  • Your thoughts are determined by your attitude and the way you deal with things. You must be positive but realistic at the same time. You must also be intuitive but logical. This means you’ll be more productive.
  • You also need to know how to tolerate frustration and trust yourself. However bad things might be, you have the resources to plan and take action accordingly.
  • Try aerobic exercise. That’ll make it easier for you to oxygenate and nurture important areas of your brain, such as white matter.

Finally, it’s worth remembering that you need to avoid falling into the trap of having a reactive brain that only anticipates danger and threats. In fact, it’s remarkable how easily this can happen. What’s important is for you to know how to make plans for when something’s worrying you. Thus, make a plan for when that happens. If you do that, you’ll have transformed yourself into a proactive person.

All cited sources were thoroughly reviewed by our team to ensure their quality, reliability, currency, and validity. The bibliography of this article was considered reliable and of academic or scientific accuracy.

    • Alexander Olsen, Emily L. Dennis, Kari Anne I. Evensen, Ingrid Marie Husby Hollund, Gro C.C. Løhaugen, Paul M. Thompson, Ann-Mari Brubakk, Live Eikenes, Asta K. Håberg. “Preterm Birth Leads to Hyper-Reactive Cognitive Control Processing and Poor White Matter Organization in Adulthood.” NeuroImage. Volume 167, 15 February 2018, Pages 419-428. DOI: 10.1016/j.neuroimage.2017.11.055
    • Martin Wohlwend, Alexander Olsen, Asta K. Håberg, and Helen S. Palmer. “Exercise intensity-dependent effects on Cognitive Control Function During and After Acute Treadmill Running in Young Healthy Adults.” Frontiers in Psychology (2017) DOI: 10.3389/fpsyg.2017.00406

This text is provided for informational purposes only and does not replace consultation with a professional. If in doubt, consult your specialist.