Categorizations and Heuristics

Lesson objective:

In this lesson, we will learn about the brain’s ability to quickly identify different sensations and form a response. It creates new categories of feelings and experiences, and relies on biases. A bias is a collection of mental abbreviations based on previous experiences and inferences that help in the rapid response of repetitive situations.

So, our brains are constantly making and relying on associations. Let’s have a closer look. 

Our various learned associations are intended to make the job of survival quite a bit easier. It’s not always so simple–but in principle, our various associations make it easier for us to rapidly identify, adapt, and succeed in surviving a complex and dangerous world. 

These are important concepts to understand as we think about how the brain and body respond to chaotic, stressful, and traumatic events. 

As we grow, our experiences change. Our world gets bigger and our experiences more diverse as we age, and it is often the case that a new experience may not align neatly with previous associations.

In an unpredictable world, how does our brain make sense of new, possibly dangerous experiences in the world around us? 

It relies on what we call heuristics

The concept of heuristics is not unique to issues related to stress and trauma. Heuristics are fundamental to how the human brain works, and similarly to associations, make survival much easier.

Let’s return to the image of the airport control tower. 

Imagine the engineer in the tower sees an incoming object, but it is a new object, one he has not seen before. He needs a way to identify it, in order to coordinate the appropriate response—to ignore it, to take  some precautionary measures, or to prepare the airport for danger.

Though the engineer has not seen this object before, he has a feeling that it deserves his attention; he makes inferences based on similar experiences and similar objects. He relies on broad categories of things that may be similar to this new object. He then makes an educated decision based on experience and inferences, in service of ensuring the safety of the airport. 

Given the complexity of our world, it would be difficult to survive if we had to stop and think every single time we had a feel

ing or had a new experience, and had to make brand new categories for those feelings and experiences. We thus often rely on heuristics or biases, which are essentially mental shortcuts based on past experiences and inferences that aid in rapid response to recurring and novel situations

We’re born with certain heuristics, inherited from our ancestors, and in other cases, we develop heuristics unique to ourselves, based on life experiences. 

Heuristics do not guarantee an optimal or even rational conclusion on how to confront a given scenario, but they are nevertheless sufficient for reaching an immediate, short-term goal or approximation

In our previous example–does the engineer need to know exactly the details of the new possible threat to the airport before making a decision?


In fact, waiting too long for complete information may result in a catastrophe. He needs to act fast, to act preemptively. 

He needs a useful approximation that ensures the safety of the airport. 

In other words, meeting a short-term goal is more important than being “correct.” Efficiency over accuracy. Utility over rationality. That is how heuristics work. 

Importantly, heuristics will sometimes lead us to incorrect, or even harmful conclusions. The engineer may overcompensate and mobilize the national guard and civil defense for what turned out to be no threat at all. 

However, heuristics are all about survival, often at the expense of accuracy. We need to be able to tell, relatively quickly, a hot fire from a block of ice, or a safe person from a dangerous person. And heuristics develop in the brain to accelerate these rapid decisions.

For example:

Sometimes, we seem to see “faces” in objects that are not even human. We’re so used to seeing faces and rapidly interpreting the quality of an interaction based on people’s expressions that we’re prone to see faces even where there isn’t a face. This is a heuristic, a mental shortcut that sometimes doesn’t reflect reality. 

In another example, when we interact with someone from a group of people we don’t like or don’t know, we often tend to assume the worst. If they do or say something that raises some red flags, we often assume that 

their behavior stems from who they are as a person. Whereas, if someone we know, or someone from our group said or did the same thing, we are usually much more willing to make excuses and provide justifications for their behavior. This tendency to defend our in-group and assume negatively about out-groups is another common heuristic. 

Overall, your brain relies on associations and heuristics to keep you safe and able to succeed in the world around you. 

Your brain uses associations and heuristics to as quickly as possible notice what in the world around you poses a risk to your safety and survival. Many times, these heuristics are not reflective of reality, and can be even harmful. We’ll get to that later. 

And here we can turn to an important counterpart of associations and heuristics, and that is predictions, and the predictive nature of the human brain. Stay tuned.