We all like to think of ourselves as logical and rational people. The reality of the matter is that none of us are.

Researchers used to believe that most people made logical, rational, and well-considered decisions. In recent years this assumption has proven to be wrong many times over. Psychologists have uncovered a long list of so-called “mental errors.” The mental errors influence our way of thinking. They do this by pushing us to make emotional, irrational, and even confusing choices.

Here are some of the most common mental errors. You’ll see how they influence our decision-making abilities.

Survival Bias

Also known as survivorship bias, this is a logical error most people make on a daily basis. Survival bias happens when people make assumptions about other people or organizations. These people/organizations have passed some milestones in the past.

Things like:

“8 Things Successful People Do Every Day” or,

“What Do the Most Successful Companies Have in Common,”

are examples of survival bias.

This particular logical error works by employing the “correlation proves causation” fallacy. In other words, these examples do not take into account any of the people or companies that have used the same strategies and have failed. Several successful companies may have something in common. However, that doesn’t mean any particular thing caused their success.

The Availability Heuristic

A mental shortcut that works by giving greater relevance to immediate thoughts. These come into people’s minds when evaluating any given topic, idea, or decision. In short, the availability heuristic says that:

if you recall a thought, then it must be more critical than any counter-arguments brought against it.

This mental shortcut may have served humankind in the past. Back then new information was scarce. However, now, it can backfire on us.

We now have immediate access to information. We see the latest news on TV or the internet. This news influences our decision-making abilities. For instance, it is a well-known fact that we are now living in the most peaceful era in human history. Even so, more and more people are convinced otherwise. Because of the exposure to the 5 o’clock news on a daily basis. It tends to overinflate the size of specific events. This increased information availability leads people o refute any evidence that proves otherwise.

The Clustering Illusion

This mental error shows our tendency to see specific patterns where there aren’t any. People are bad at detecting and understanding randomness. They think they are looking at particular patterns or clusters. In fact, there is nothing unusual there. We tend to think of randomness as a sort of perfect distribution of opposing events. Every sequence that breaks away from that ideal distribution must, thus, not be random.

Even so, given enough time, anything that can happen will happen. Some patterns or clusters that we observe can be an expression of that. It works like the so-called “infinite monkey theorem.” The one where a monkey is hitting typewriter keys at random for an infinite amount of time. Given that endless time, the monkey would type the complete works of Shakespeare.


These are a few examples of mental errors that keep us from making right decisions. There are plenty of others to choose from.

From an evolutionary perspective, however, these cognitive biases, offer the brain some “shortcuts.” These biases prevent the brain from overloading from the many tasks it has to do on a daily basis.

Still, we are all so accustomed to taking these shortcuts that we don’t even realize when we are using them. We don’t see how they can affect our decision-making process. Self-awareness is the best way to fight against these errors before we make them.