Biases

Each definition here is taken from Wikipedia.

Confirmation bias

The tendency to search for, interpret, favor, and recall information in a way that confirms or strengthens one's prior personal beliefs or hypotheses.

Self-fulfilling prophecy

Self-fulfilling prophecy refers to the socio-psychological phenomenon of someone "predicting" or expecting something, and this "prediction" or expectation comes true simply because one believes it will, and their resulting behaviors align to fulfil those beliefs.

Halo effect

Halo effect is the tendency for positive impressions of a person, company, brand or product in one area to positively influence one's opinion or feelings in other areas. Is the opposite of the horn effect.

Horn effect

The horn effect, closely related to the halo effect, is a form of cognitive bias that causes one's perception of another to be unduly influenced by a single negative trait. An example of the horn effect may be that an observer is more likely to assume a physically unattractive person is morally inferior to an attractive person, despite the lack of relationship between morality and physical appearance.

Loss aversion bias

Loss aversion refers to people's tendency to prefer avoiding losses to acquiring equivalent gains: it is better to not lose $5 than to find $5.

Reactance theory

When free choice is limited or threatened, the need to retain our freedoms makes us desire them (as well as the goods and services associated with them) significantly more than previously.

When increasing scarcity-or-anything else interferes with out prior access to some item, we will react against the interference by wanting and trying to posses the item more than before.