Cognitive biases are unconscious and systematic errors in thinking that occur when people process and interpret information in their surroundings and influence their decisions and judgments (Kahneman et al., 1982). These biases can distort an individual’s perception of reality, resulting in inaccurate information interpretation and rationally bounded decision-making (Kahneman, 2011). Cognitive biases are often seen as flaws in the rational choice theory of human behavior, which asserts that people make rational choices based on their preferences. Broadly speaking, bias is a tendency to lean in favor of or against a person, group, idea, or thing, usually in an unfair way. Biases are natural — they are a product of human nature.
In psychology, there are two main branches of biases: conscious and unconscious. Conscious or explicit bias is intentional — you are aware of your attitudes and the behaviors resulting from them (Lang, 2019). On the other hand, unconscious bias, or cognitive bias, represents a set of unintentional biases — you are unaware of your attitudes and behaviors resulting from them (Lang, 2019). We often rely on mental shortcuts (called heuristics) to help make sense of the world with relative speed. As such, these errors tend to arise from problems related to thinking: memory, attention, and other mental mistakes. These biases occur as an attempt to simplify the complex world and make information processing faster and easier. For example, we might assume someone’s gender based on their profession.
Confirmation bias. The tendency to search for, interpret, or remember information in a way that confirms one’s preconceptions or hypotheses. For example, if you believe that apples are unhealthy, you might only pay attention to news and studies that confirm that view and ignore any evidence to the contrary. This type of bias can lead people to make poor decisions, because they are not considering all of the available evidence.
The availability heuristic. The tendency to overestimate the likelihood of events that are easy to imagine. This bias is often responsible for people’s fear of flying, even though it is statistically much safer than driving. The availability bias can lead people to make irrational decisions based on feelings rather than facts.
Anchoring bias. The tendency to rely too heavily on the first piece of information when making a decision. For example, if you are trying to decide how much to spend on a new car, you might anchor your decision on the sticker price, without considering other factors like monthly payments or fuel efficiency. This bias can lead people to make poor decisions by not considering all the relevant information.
Overconfidence bias. The tendency to be overly confident in one’s own abilities or judgments. This bias can lead people to take unnecessary risks or make poor decisions based on their own overestimation of their abilities.
Hindsight bias. When people claim to have known something all along, after it has been proven true. For example, after attending a basketball game, claiming you knew who was going to win beforehand.
There are new cognitive biases being added to the list every day. Like “the cheerleader effect,” coined by the character Barney on the TV show How I Met Your Mother. That is, the bias that makes us think individuals are more attractive when in a group.