False uniqueness bias

…The tendency of people to see their projects and themselves as more singular than they actually are.

False consensus effect

… The tendency for people to overestimate the degree to which others agree with them

Bandwagon effect

… The tendency to do (or believe) things because many other people do (or believe) the same. Related to groupthink and herd behavior

Empathy gap

… The tendency to underestimate the influence or strength of feelings, in either oneself or others

Groupthink

… Where the desire for harmony or conformity in the group results in an irrational or dysfunctional decision-making outcome.

Shared information bias

… The tendency for group members to spend more time and energy discussing information that all members are already familiar with (i.e., shared information), and less time and energy discussing information that only some members are aware of (i.e., unshared information).

Illusion of asymmetric insight

…People perceive their knowledge of their peers to surpass their peers’ knowledge of them

Illusion of transparency

… People overestimate others’ ability to know themselves, and they also overestimate their ability to know others.

Dunning–Kruger effect

… The tendency for unskilled individuals to overestimate their own ability and the tendency for experts to underestimate their own ability

Curse of knowledge

… When better-informed people find it extremely difficult to think about problems from the perspective of lesser-informed people

Illusory superiority

… Overestimating one’s desirable qualities, and underestimating undesirable qualities, relative to other people. (Also known as “better-than-average effect”, or “superiority bias”.)

Naïve realism

… The belief that we see reality objectively and without bias; that the facts are plain for all to see; that rational people will agree with us; and that those who don’t are either uninformed, lazy, irrational, or biased.

Just-world hypothesis

… The tendency for people to want to believe that the world is fundamentally just, causing them to rationalize an otherwise inexplicable injustice as deserved by the victim(s).

Ambiguity effect

… The tendency to avoid options for which the probability of a favorable outcome is unknown

Anchoring

…. The tendency to rely too heavily, or “anchor”, on one trait or piece of information when making decisions (usually the first piece of information acquired on that subject)

Doubling Down

… Or Backfire effect. The reaction to disconfirming evidence by strengthening one’s previous beliefs.