Our non-conscious systems primarily work using pattern recognition. Through a combination of genetic pre-programming and repeated exposure, your brain learns to label instances of things in the world as “dangerous” or “not dangerous”, “food” or “not food”, “person” or “not person”, “real smile” or “fake smile”. It learns to categorize and predict automatically.

When you see a chair you are immediately able to recognize it as a chair and associate it with your concept of chair, even if it is the largest chair you have ever seen, or the first one you’ve seen with a zebra stripe pattern. Your brain has effectively developed a way to rapidly recognize things as being “chairs” or “not chairs” based on whether they match a certain pattern. This pattern was learned automatically from exposure to many chairs in the past. You don’t have to consciously consider whether this particular object has the features necessary to make it a chair, your brain produces an answer before you are even aware of thinking about it.

To give another example, consider what happens when a chess Grandmasters looks at a chess board. In many cases, they are able to glance at a board positions and immediately (without conscious thought) identify them as being strong or weak, with good reliability. Of course, they might then choose to reason consciously about the positions in order to check or improve upon their gut responses.

Having considered these two ways of making predictions and decisions, the question then arises: when should we rely on thorough conscious analysis, and when should we use our automatic processing? To answer this, let’s consider the advantages and disadvantages of these two approaches.

Careful Conscious Analysis

Advantages

• Handles problems where multiple logical deductive steps are necessary to find a solution (e.g. I know that all A’s are B’s, and also that if something is a C it cannot be a B, therefore this particular A is not a C.)
• Allows the application of theories to problems, and in doing so lets you leverage the research and thinking of others (e.g. what does economic theory tell us will happen to soybean prices when the supply of soybeans dries up?)
• Allows you to develop theories of your own which can then be applied in future situations. (e.g. I’ve noticed that when I attack him on his left side he parries and counter attacks. So this time I will initiate a fast attack to the left, and as he begins to parry, I will drop the point of my blade to get underneath his sword, and carry the momentum into an attack to the right instead)
• Lets you compare the advantages and disadvantages of multiple possible methods or solutions. (e.g. The first theory predicts results will come out a certain way, but the second predicts a slightly different outcome. However, the first theory has a better track record on cases like this one.)
• Produces reasoning that can be communicated to others. (e.g. I came to my conclusion by evaluating the randomized controlled trials and noting that…)

Disadvantages

• Unless you have honed your truth discernment skills, you may fall prey to logical fallacies, become misled by cognitive biases, or rely on theories that have not been empirically validated. Performing truly excellent and reliable conscious analysis takes work, skill, self correction, good habits of mind, knowledge about potential pitfalls, and practice. (e.g. Due to the compatibility of your astrological charts, I think that he would make an excellent husband.)
• Thinking carefully is a slow process. (e.g. There is a deer in the road about thirty feet ahead of me and I’m going 60 miles per hour. If I hit the brake now will I have time to stop before I hit it? Will it be more or less dangerous to me if…)

Unconscious Automatic Processing

Advantages

• Operates fast (e.g. That ball he hit is going out-of-bounds so there is no need to run and try to catch it)
• Can be used in lots of situations where feedback is readily available, even when you don’t have a theory about how to solve the problem consciously (e.g. Now when I look at a cubist work I immediately know if is by Picasso, Braque or someone else, even if I’ve never seen it before.)
• Starts to get trained automatically without effort if you just do something enough times (e.g. Having listened to enough songs that I knew the titles of, I can now often guess what the title of a song is just from its lyrics)

Disadvantages

• Cannot effectively handle all types of problems. This method is especially bad for problems that require long deductive chains to solve, or where gathering various sorts of evidence together is necessary. (e.g. I know that the randomized controlled trials say otherwise, but my own experiences as a psychologist still tells me that psychodynamic therapy is more useful and cost-effective for treating depression than Cognitive Behavioral Therapy)
• May give you wrong answers when the problem changes compared to what you have been trained on (e.g. I know we’re playing squash now, but that move I did would have been perfect if we were playing tennis!)
• Requires repeated exposure, so won’t work well when you don’t get to practice a lot or see examples over and over again. (e.g. Well, I’ve only done heart surgery two times before, but from what I can tell this doesn’t quite seem to be in the right place, so I’m going to abandon the standard procedure and improvise)
• Doesn’t always provide us with conscious insight into why the prediction came out a certain way (e.g. I know that thing is designed to put food onto, but it still looks like a chair to me)

Careful analytical thought, and automatic processing relying on pattern matching are both extremely useful ways of approaching problems. When processing needs to be done quickly and you can train yourself through lots of examples with feedback, automatic processing may provide the best method for making predictions. But when chains of logical deduction are required, or evidence needs to be gathered and evaluated, or repeated exposure is not possible, or strong predictive theories exist, then as long as you have honed your thinking skills sufficiently well, conscious analysis will probably provide the best results.

It is common to hear advice that amounts to “going with your gut,” “trusting your instincts,” or “following your intuition.” But these suggestions seem to indicate that the answers we arrive at through careful thought are sometimes (or perhaps usually) inferior to our immediate reactions. 

Consider the following representative quotes:

Keep the faith, don’t lose your perseverance, and always trust your gut extinct. – Paula Abdul, Performer

I always trust my gut reaction; it’s always right. – Kiana Tom, Television Host

Intuition comes very close to clairvoyance; it appears to be the extrasensory perception of reality. – Alexis Carrel, Nobel Prize Winner (Medicine)

Before making a decision about whether to trust our gut, it seems like a worthwhile endeavor to first try to understand what exactly our “gut” is. 

There are a number of (non-mutually-exclusive) possibilities:

1. Sometimes, gut feelings can be explained by our evolved instincts that are encoded in our DNA, which exist because they helped our ancestors survive in the world as it was hundreds of thousands of years ago. For example, we are likely to feel anxious when confronted with something unfamiliar (a large unknown animal, for example) or feel fear when we hear a loud noise. These sorts of reactions are very useful at times but typically only work well in scenarios involving danger or conditions that are similar to those that our prehistoric ancestors encountered. At a birthday party where balloons are being popped, a fear of loud noises is not useful. On the other hand, when walking in a canyon, a loud noise might indicate a cascade of rocks, and a fear response might save your life.

2. In many cases, our intuition is associated with our immediate emotional responses to stimuli. For example, we might get a positive feeling towards someone who has a warm smile or feel negatively towards a person who is raggedly dressed. 

While our emotional responses clearly are important (e.g., it’s important to feel sympathy towards a friend when they look sad and to feel fear when encountering someone who has hurt you in the past), they can also be distorted and counter-productive. For example, many people feel slighted if a friend fails to return their phone call. However, one is likely to feel better about the situation (despite his initial emotional response) if he reminds himself that there are all sorts of reasons that a friend doesn’t return calls, including being temporarily busy or absent-minded. On the other hand, those who trust in their initial response of hurt and anger (which might stem, for example, from a lack of confidence or insecurity) are more likely to blow up at the friend or act coldly during the next encounter, which could damage a generally fulfilling relationship. 

Unfortunately, it can be tricky to differentiate between emotional responses that are useful and improve our lives and those that are based on misperceptions and are unhelpful. Both of these types of emotional responses feel equally real when you are experiencing them, and it is often only when we carefully scrutinize them from a neutral point of view that we can tell the difference.

3. Sometimes, our “intuition” is based on repeated experiences that we access automatically. For example, a surgeon might get an uneasy feeling during an operation, which could be triggered automatically when she notices similarities between the current patient and difficult surgical cases she has had in the past. Another example would be a painter who suddenly has an impulse to add more thinner to the paint he is using, which could be a subconscious reaction based on years of art-making experience. 

Generally, when we repeat similar tasks enough times, their execution becomes automatic and begins to feel like an instinct. We might then say that we have developed an intuition for effectively completing the tasks. These kinds of responses can occur much faster than those controlled by conscious thought and thus can be very efficient and useful. Of course, if the initial learning phase that leads to one’s intuitions is not of good quality (e.g., we complete the task poorly while learning), the intuition will be of poor quality as well. 

Sometimes intuitions of this form are experienced in emotional form as an uneasy feeling, in particular when our (possibly subconscious) expectations (based on experience, training, or practice) do not match what we see. A day trader, for example, might decide to sell a stock due to an uncomfortable feeling about it. In reality, what may have happened is that the stock chart had a pattern that did not conform to his expectations. This intuition can be quite useful since those cases that don’t match our predictions can be especially difficult, require special attention, and present unknown hazards.

4. Societal conditioning can create a kind of gut reaction that operates without conscious awareness. If we are told enough times when we are young not to trust strangers, then we may feel immediately distrustful when a stranger strikes up a conversation. The trouble with responses of this kind is that they are often formed without thought or careful reflection. For example, if we grow up in an area where a lot of racism is present, we might be told that certain races are inherently dishonest and so could have strong intuitive reactions to people of those races based on this idea. Or if we are taught to believe that black cats bring bad luck, we might start feeling uneasy in a house with a black cat. Since the ideas that society conditions us with may not be true, it can be very valuable to be aware of these automatic reactions and to carefully evaluate their logical and empirical validity.

5. Our brains are capable of forming very strong associations (for instance, between the smell of a perfume and a particular person), and this can lead to what might be interpreted as “gut feelings.” For example, if we were attacked by dogs when we were young, we may feel anxious around dogs later in life, even when we know on an intellectual level that we are safe around them. Such associations clearly have a valuable survival purpose, but on the other hand, they can push us into self-defeating behavior (like refusing to visit the house of a friend because she has a dog). Our brain’s natural tendency is to be “better safe than sorry,” as your ancestors were very unlikely to die from forming spurious associations (such as that dogs are generally dangerous) but were at real risk of dying if they failed to form certain real associations (such as that tigers are dangerous).

As we can see, what people call their “gut” is most likely a hodgepodge of various brain activities, which include survival instincts, emotional responses, automatic recall of learned information, societal conditioning, and associations. 

It is not at all obvious that these systems will lead to good decision-making in general. Each has its very important uses, as well as significant domains where it will fail. A businessman cannot rely on fight or flight instincts when giving an important presentation, a person with an anxiety disorder cannot expect his emotional responses to be accurate representations of reality, a doctor cannot rely on his old impulses when learning a totally new surgical technique, and no-one can expect that their society will condition them only with true information. Hence, to make truly good decisions, it is essential to evaluate your intuition to see whether it is likely to be accurate in the situation at hand. Each time our gut tells us something, we cannot know whether to trust it until we understand where that feeling originates from.

Note (January 13, 2022): For more about when to trust your gut, watch my TEDx talk here.

If you liked this essay, you may also enjoy a later essay I wrote, which fleshes out the specific circumstances under which it might be advisable to trust your intuition: The FIRE Framework: deciding when to trust your gut