What Are Cognitive Biases: Types, List and Examples

Cognitive biases represent the psychology of man's evaluation errors, a form of evaluation distortion caused by prejudice, the result of our need to efficiently process the flow of sensory information from the outside world. Cognitive biases are also techniques and principles that influence people's conscious minds, mainly used in marketing and persuasion. With this psychology article we will see together what cognitive biases are and their types , also proposing a list with examples.

What is a cognitive bias?

First, we will look at the definition of cognitive bias. The bias, in cognitive psychology, indicates a judgment that does not necessarily correspond to the evidence , developed on the basis of the interpretation of the information in possession, although not logically related to each other. In other words, cognitive bias is a systematic pattern of deviation from the norm or rationality of judgment.

In psychology, a bias is a tendency to create one's own subjective reality , not necessarily corresponding to the evidence, developed on the basis of the interpretation of the information in possession, although not logically or semantically related to each other, which therefore leads to to an error of appreciation or to the lack of objectivity of judgment. Therefore, by contributing to the formation of judgment, cognitive bias can influence an ideology, an opinion and a behavior.

What are heuristics?

With little valuable time available to process so much information, our cognitive system is fast and essential, specializing in mental shortcuts: heuristics, in effect, are thinking strategies that allow quick and efficient judgments . The speed of these intuitive guides promotes survival, however in some situations rush causes errors . Let's look at some types of heuristics:

  • Representativeness heuristic : instant judgments to decide whether someone or something fits into a category, such as deciding that a person is a librarian rather than a waitress, because it better represents the image of the librarian. You can reduce the weight of other important information.
  • Availability heuristic : quick judgments about the probability of events (based on memory availability), how to assess adolescent violence after school shootings. It can lead to attributing too much weight to a lived situation and therefore, for example, being afraid of the wrong things.
  • Heuristic of simulation or counterfactual thinking : ease with which a hypothetical scenario can be recognized, such as feeling angry because the train has been missed for two minutes and because it could be done differently very easily. It can lead to living in regret or giving too much importance to luck.
  • Anchoring and accommodation heuristics : estimating some value from an initial value to which the new object accommodates, such as judging the cost of a dinner at a restaurant based on information from a friend. It can lead to underestimating or overestimating the person or object in question.

Cognitive biases in communication and marketing

Knowing the cognitive biases allows an advertiser, a creative or a marketer to anticipate communication options, to anticipate behaviors, but above all to respond to the needs of consumers. It is no coincidence that successful advertising strategies are always based on satisfying the latent or pressing needs of customers. Neurobranding strategies use biases to support the creation of each communicative product: from the installation of a store to the creation of a site, from the idea of ​​a TV ad to paper advertising, from the management of messages in the social networks until the creation of an advertising campaign. See some types of cognitive biases and examples applicable in these areas will help us understand how cognitive biases work:

  • The bandwagon effect : use the numbers to convince. It is one of the most used biases, but certainly also the most effective, the one that sees us inclined to believe in something because many do. In fact, one thing is to be reached by a campaign that tells us to "try this incredible product", another is if they tell us "this product has already been bought and appreciated by more than 5000 women like you" especially if we use a subject similar to we want to convince (professional, woman, mother, doctor, etc.).
  • Ben Franklin effect : offer resources in exchange for data. One of the most effective techniques is to offer a resource in exchange for something (technically called a master). For example, a discount , access to exclusive promotions, etc. This not only exponentially increases the probability that users leave us their sensitive data, but above all that they give us their real data, if we make the resource reach them precisely through the latter (for example, by message or email) , because they are interested in receiving it.
  • Loss aversion : you can't miss this offer. The loss aversion , coupled with the scarcity principle is undoubtedly one of the trends most exploited, particularly campaigns aimed at performance. Limited-time offers , with a countdown countdown, "that will never be repeated", "that you definitely cannot miss" are the order of the day, although it must be said that, by abusing this bias, you are likely to lose credibility (use sparingly and honestly).

Examples of cognitive biases

We can divide cognitive biases into four broad areas based on the 220 biases compiled, organized, and described by Buster Benson and John Brady (2018). Here are some examples:


When things don't make enough sense to us, we fill in the gaps and generalize.

  • We imagine things and people with which we are familiar as better than those with whom we are not familiar: cross-race effect, cheerleader effect, halo effect, etc.
  • We simplified the probabilities and numbers to make them easier to think about: Murphy's law, normality bias, survival bias, etc.
  • We think we know what others are thinking and we assume that others know what we know: Othello error, obsequiousness bias, illusion of transparency, etc.
  • We project our current mindset and our assumptions on the past and future: outcome bias, end-of-story illusion, impact bias, etc.
  • We fill the gasp in the information of our stereotypes, generalities , and experiential stories: automotive bias, authority bias, car effect etc.
  • Our brain imposes stories and patterns on the world, even from scarce data: recent illusion, regression fallacy, evidence of absence bias, etc.

Simple explanations

When we feel there is not enough time to find out, we look for what seems easy and familiar and doable.

  • We prefer what seems simple or has more information about what seems ambiguous or complex: precision bias, Occam's razor, ambiguity bias, etc.
  • We prefer to finish things in which we have already invested time and energy : Ikea effect, zero risk bias, loss aversion etc.
  • We want to maintain our autonomy and status, and avoid irreversible decisions: reverse psychology, social comparison bias, status quo bias, etc.
  • We gravitate towards the immediate, relatable and close , on the delayed and distant: identifiable victim effect, hyperbolic discount, appeal to novelty.
  • To get things done, we need to feel confident in our abilities, and feel that what we do is important: optimistic bias, illusion of control, fundamental attribution error, etc.

Information selection

When too much information reaches us, we become selective in what we notice.

  • We tend to notice flaws in other people more than we notice flaws in ourselves : naive cynicism, blind spot bias, naive realism.
  • We attend to what seems unusual or surprising , omitting information that seems ordinary or expected: negativity bias, horn effect, humor effect, etc.
  • We notice the change , but we evaluate it more by a + or - direction than if we see the item in its changed state: Weber-Fechner law, money illusion, anchor, etc.
  • We are attracted to details that confirm our existing beliefs , and we tend to ignore details that conflict with them: observer effect, expectation bias, ostrich effect, etc.
  • We tend to notice things more when they relate to what has recently been loaded into our memory: empathy gap, attentional bias, context effect, etc.

Consideration of importance

When we are not sure what we need to know or remember, we choose only what we think is important.

  • We edit and reinforce some memories after the fact, often exchanging or injecting new details: origin confusion, Pollyanna principle, false memory, etc.
  • We tend to discard specificities to form generalities , drawing stereotypes, biases, and implicit associations: stereotyped biases, negative biases, fading affective biases, etc.
  • We store memories differently based on how we experience them and what was important to us at the time: Google effect, test effect, next line effect, etc.
  • We reduce events and lists to their key elements and photo elements to represent the whole: memory inhibition, suffix effect, memory bias, etc.