List of Cognitive Biases _ Student Reference Sheet
Ronee Pillsbury-Hunter
Cognitive Bias
The brain is carrying out trillions of mental processes constantly looking for strategies to apply
when making complex decisions and judgments. In our attempt to simplify information
processes, we may take mental shortcuts that lead us down the wrong path. Cognitive bias is
the thinking error that we make when we are processing information.
Cognitive biases develop for several reasons. It is thought that cognitive bias helps us process
information more quickly. Therefore, cognitive biases can cause us to make inaccurate
judgments, decisions, and interpretations.
Because we are constantly making judgments and processing information, we are constantly at
risk for cognitive bias. Although it is impossible to avoid cognitive biases, it is possible to
understand what they are so that we can look for them when they arise and adjust our
judgments as needed.
List of Cognitive Biases

Self-Perception Biases: Self-Perception biases are the tendency to allow one’s disposition to
affect one's way of interpreting information. Self-perception biases are distortions of one’s
own view of self.
Bias Blind Spot – is the affectation or tendency to be ignorant of one’s own biases. (Pronin
and Kugler, 2007)
Illusion of Control - is the belief of being in some control over events and outcomes that
you actually have no effect on. (Kahneman and Tversky, 1972)
Restraint Bias – is having overconfidence in one’s own ability to deny temptations.
Self-Serving Bias - is the tendency to be less prone to claim a failure than to claim a success.
People think their success is due to their own brilliance, but their errors are a result of
mistakes outside of their control (cognitive dissonance).
Overconfidence Effect – This is an unusually high confidence in one’s own answers,
opinions, or beliefs. (Pohl, 2006)
Egocentric Bias – is the tendency to make ourselves look better than what we really are.

Perception Biases: Perception biases are inaccurate views or conclusions drawn in various
ways. People may believe they are able to evaluate an event fairly and accurately, including
making judgments about situations, but a number of biases interact with the way they
perceive events (witness testimony, pictures shown to juries).
Attentional Bias – is the tendency for one’s emotions to determine or affect one's focus
(marketing –starving children).
List of Cognitive Biases _ Student Reference Sheet
Ronee Pillsbury-Hunter
Availability Heuristic - basing judgments or estimations on what most easily comes to
memory.
Hindsight Bias - The “I-knew-it-all-along bias,” it is the tendency to believe you knew
something beforehand (nagging thought in your mind). This also includes viewing
completed events as more predictable than they actually were. (Pohl, 2006)
Observer Expectancy Effect / Selective Perception - known as the “observer effect” It is the
tendency to manipulate or misinterpret data so that it will support (or disprove) a
hypothesis. Essentially, it is the tendency to see what you want or expect to see.
Framing Effect - the tendency to interpret information differently based on changes in
context or description (text vs quiz).
Choice Supportive Bias - the propensity to believe your choices were better or more
righteously chosen than they actually were. An individual remembers only the positive
aspects of the chosen option of a decision, and only the negative aspects of the rejected
options.

Logic and Decision Biases: What is logical is not always true. Logic and Decision biases relate to a
person’s tendency to make decisions based upon what is logical according to their worldview.
Base Rate Fallacy - Base Rate Fallacy is the inclination for someone to base his judgments
on specifics rather than the big picture (narrow scope).
Zero-Risk Bias - is a tendency to prefer the complete elimination of a risk even when
alternative options produce a greater reduction in risk (overall).
Anchoring – is the inclination for someone to allow one piece of information to outweigh
others when making a decision.
Belief Bias - the tendency for someone to ignore logical error in an argument based on how
believable a conclusion may be (weight loss).
Semmelweis Reflex - the reflex-like tendency to ignore or reject any contradictory
information against what one already believes.

Probability Biases: A probability bias arises when someone misinterprets precedents or
past information and acts on this inaccuracy.
Normalcy Bias - This is a logical error based on previous experience (Hsee and Zhang, 2004)
Gambler’s Fallacy - the propensity to believe that happenings of the past determine what
will happen in the future. (Hsee and Zhang, 2004)
List of Cognitive Biases _ Student Reference Sheet
Ronee Pillsbury-Hunter

Predictive Biases: Predictive biases relate to a person holding the inaccurate belief that
they prematurely know information about events or people based on large or general ideas
rather than specifics.
Optimism Bias - is the higher tendency to expect positive outcomes of planned actions,
rather than negative. Optimists tend to be the reassuring, confidence boosting,
Pessimism Bias - opposite of the Optimism Bias, this is the habit of anticipating negative
outcomes rather than positive. Pessimists typically have less hope for success of planned
actions.
Planning Fallacy - this is the tendency to miscalculate the time necessary to complete a
task.
Stereotyping - a bias in judgment, stereotyping is setting expectations for / or drawing
conclusions about an individual, based on their associated group. Racial, religious, and
political stereotyping is most common.

Conformity Biases: Conformity bias is a tendency to behave similarly to the others in a
group, even if doing so goes against your own judgment.
Availability Cascade - is the idea that if you believe something enough, it becomes the
truth. This idea is subjective to each individual.
In-group Bias - the tendency for someone to be more comfortable or friendly with people
whom he perceives as like himself, or as in the same group as himself.
Out-group Homogeneity Bias - also called homogeneity blindness, this is the tendency for
people within a like group to see their group members as more varied and individualistic
than the members of other groups.
System Justification - the “go with the flow” tendency for people to more frequently
adhere to precedents, rather than establish something new or different. (Edwards, 1968)