From Wikipedia

A stereotype is an exaggerated belief, image or distorted truth about a person or group — a generalization that allows for little or no individual differences or social variation. Stereotypes are based on images in mass media, or reputations passed on by parents, peers and other members of society. Stereotypes can be positive or negative. (from Southern Poverty Law Center)

One theory as to why people stereotype is that it is too difficult to take in all of the complexities of other people as individuals. Even though stereotyping is inexact, it is an efficient way to mentally organize large blocks of information. Categorization is an essential human capability because it enables us to simplify, predict, and organize our world. Once one has sorted and organized everyone into tidy categories, there is a human tendency to avoid processing new or unexpected information about each individual. Assigning general group characteristics to members of that group saves time and satisfies the need to predict the social world in a general sense.


Possible prejudicial effects of stereotypes are:

Some of the stereotypes we typically encounter in ourselves and others can include:

World Map of Useless Stereotypes.jpg

The World Map of Useless Stereotypes by Christoph Niemann


I think you get the picture - any and all characteristics can, in our minds, create a picture of that entire person and place that individual into a stereotypical group. It is not just characteristics that set an individual apart that creates a stereotype, but also characteristics that cause us to place an individual as a member of a group, then infer that that individual is exactly like all other members of that group or that all members of that group are like that individual.That picture can then influence our judgments about that individual. Stereotypes can be positive (blonds have more fun) or negative (the Irish drink too much) in their original intent, but are still an abbreviated and inaccurate characterization that can cause harm.


In the video below, Dr. Leeno Karumanchery, President and CEO of Diversity Solutions Inc., explores some of the complexities involved in how and why women and other minoritized groups get stereotyped.


And one more short 3 minute video: Ouch! That Stereotype Hurts!




From Wikipedia

Bias is an inclination to present or hold a partial perspective at the expense of (possibly equally valid) alternatives. Bias can also be defined as:

Many of the human behaviors we discuss under this topic are technically known as biases, and also because the normal meaning of "bias" refers to our noticing these sorts of behavior in someone else. When a behavioral economist says that people in general have some specified bias, he is saying that people tend to behave in a way that is wrong according to the theories of his or her field.

Bias can come in many forms. Anything biased is generally one-sided. A cognitive bias is any of a wide range of observer effects identified in cognitive science and social psychology including very basic statistical, social attribution, and memory errors that are common to all human beings. Social biases, usually called attributional biases, affect our everyday social interactions. And biases related to probability and decision making significantly affect the scientific method which is deliberately designed to minimize such bias from any one observer.

These processes include information-processing shortcuts, motivational factors, and social influence (Wilcox, 2011). Such biases can result from information-processing shortcuts called heuristics. They include errors in judgment, social attribution, and memory. Cognitive biases are a common outcome of human thought, and often drastically skew the reliability of anecdotal and legal evidence. It is a phenomenon studied in cognitive science and social psychology.  Bias can also be defined as an acceptance of a stereotype as fact, despite objective evidence to the contrary

We can easily see the relationships between these two terms- Stereotype and Bias: We have specific beliefs about individuals or groups based on some known characteristic (stereotype), and we have an inclination to hold a partial perspective (for or against) these people (bias) based on that characteristic.

Below are some subsets of cognitive biases with examples (from YorkPsych)

Self Perception Biases


photo credit:jcoterhals@flickr

Self Perception biases are the tendency to allow one's dispositions to affect one's way of interpreting information. Self perception biases are distortions of one's own view of self.

1.Bias Blind Spot - the affectation or tendency to be ignorant of one's own biases. This is a case of the blind not knowing or ignoring that they are blind. (Pronin and Kugler, 2007)

2. Illusion of Control - the belief of being in at least some control over events and outcomes that you actually have no effect on. The devoted fan who gets out his lucky hat that "always brings the game back whenever the Giants are down" is a good example of this bias. (Kahneman and Tversky, 1972)


Perception Biases

Perception biases are inaccurate views or conclusions drawn in various ways. They explain certain behavioral vicissitudes as well as how collective debates can result in so many various opinions.

1. Attentional Bias - the tendency for one's emotions to determine or affect one's focus. Emotional propaganda plays on this; for instance, certain charity commercials will show pictures of starving kids in Africa to draw attention away from the fact that only a fraction of the money donated actually goes to charitable causes.

2. Availability Heuristic - basing judgments or estimations on what most easily comes to memory. Because we remember cases or events that stand out as unusual or unexpected, this usually results in false assumptions or estimations. (Tversky and Kahneman, 1972) The availability heuristic is hypothesized to be to blame for the misconception that couples are more likely to conceive after they have adopted a child. People tend to remember all of the people who conceive after adoption and tend to forget about all of the cases in which the couples did not conceive after adopting.

3. Hindsight Bias - "the I-knew-it-all-along bias", it is the tendency to believe you knew something when you truly did not. This also includes viewing completed events as more predictable than they actually were. (Pohl, 2006) Hindsight Bias can easily be observed outside the science building as Yorkies walking out of a math test will ask one another what they got on the Option A and frustratedly proclaim they knew that was what they were supposed to do, but for some reason didn't apply it at the time.

Logic and Decision Biases

Cognitive biases in logic and decisions are shown mostly through how people go about solving problems in different ways, make various choices, and judge different situations.

1.Base Rate Fallacy - Base Rate Fallacy is the inclination for someone to base his judgments on specifics rather than the big picture. An example of this could be a York Senior who chooses a college for having a strong chemistry program and ignores other aspects such as its location in the middle of a desert.

2. Anchoring‍ - the inclination for someone to allow one piece of information to outweigh others when making a decision. An example might be a couple considering the fact that the girl they hired to baby sit their children goes to Stanford to be more important than the side facts that that girl skips half her classes, rides a motorcycle and brings her boyfriend with her to babysitting jobs.

Probability Biases

A probability bias arises when someone misinterprets precedents or past information and acts on this inaccuracy.

1. Normalcy Bias - the bias best represented in the freshmen class as Yorkies who are used to flying by in classes believe that since they have never received a B before, it simply cannot or will not happen. This is a logical error based on previous experience that most usually will throw the freshmen into shock. (Hsee and Zhang, 2004)

2. Gambler's Fallacy‍ - the propensity to believe that happenings of the past determine what will happen in the future. Just as its name predicts, this is most commonly exemplified by gamblers whom mistakenly tend to think along the lines that since they lost their game the last 6 times, they have a much greater chance of winning this time, or the next time, or the time after that. (Hsee and Zhang, 2004)

Predictive Biases

Predictive biases are most usually related to someone holding the inaccurate belief that they prematurely know information about events or people based on large or general ideas rather than specifics.

1. Optimism Bias - the higher tendency to expect positive outcomes of planned actions, rather than negative. People known as optimists tend to be the reassuring, confidence boosting, Mrs.Sherry-type people who always encourage you to hope for the best.

2. Pessimism Bias - opposite of the Optimism Bias, this is the habit of anticipating negative outcomes rather than positive. Pessimists sometimes suffer from depression, and typically have less hope for success of planned actions.

3. Stereotyping - a bias in judgment, stereotyping is setting expectations for or drawing conclusions about an individual, based on the group they are tied to. Racial, religious and political stereotyping are most common as one will assume that because someone looks a certain way, believes a certain way or votes a certain way, she is like the majority of all others who affiliate with them.

‍Conformity Biases

Conformity biases are the most socially based cognitive biases that are exemplified by people young and old in instances varying from politics to surfing.

1. Availability Cascade - the idea that if you believe something enough, it becomes the truth. This idea is subjective to each individual as, for instance, religious upbringing results in different people having concrete belief in opposing concepts.

2.Ingroup Bias - the tendency for someone to be more comfortable or friendly with people whom he perceive as like himself, or as in the same group as himself. This most basically explains the "cliques" of typical high school as people with common interests gravitate to each other. (Garcia, Song and Tesser, 2010)


This video by Mr. Wray, hits the winner bell on two fronts. First, it is a great overview on cognitive bias and second, it is in the form of a song.


 Here is something to carefully consider - we all stereotype, and we all have biased perceptions. We even apply stereotypes to ourselves (or they are applied by someone else) , and then modify our own behavior based on those stereotypes - I am a mature, college educated professional, and so should wear a tie to work and probably would not get a tarantula tattooed on my bald head no matter how much I wanted to.

Below is a very good video that describes what is referred to as "Self-fulfilling Prophecy", or the "Stereotype Effect". - we become what we are stereotyped as.



Unless you are a psychology or sociology major, there really is not need to memorize all the various types of cognitive biases listed above (and there are many more that aren't listed). These lists are provided so that the reader might recognize in themselves these same kinds of fallacies. These examples help us to also better understand the people around us, and how they view the world.

Let's test our understanding of these definitions with a short quiz. Don't panic, you can retry this quiz as many times as you like.

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