Example: Labelling people communists, from a particular religion to discredit claims.
Insight: The fallacy attempts to shift focus from the idea to the person holding the idea.
Insight: The goal of an ad hominem attack is to discredit the person holding ideas or claims.
Definition: The tendency to seek evidence favourable to existing beliefs, and ignore or reinterpret evidence unfavourable to existing beliefs.
Example: Lawyers purposefully employ confirmation bias as there is greater incentive to win the case rather than reveal truth.
Example: Paranoia is a form of confirmation bias - if you believe everyone is out to get you, you will view the wide variety of coincidences and anomalies in life as evidence of your belief.
Reference: Psychologist Raymond Nickerson (1998): "If one were to attempt to identify a single problematic aspect of human reasoning that deserves attention above all others, the confirmation bias would have to be among the candidates for consideration. ... it appears to be sufficiently strong and pervasive that one is led to wonder whether the bias, by itself, might account for a significant fraction of the disputes, altercations, and misunderstandings that occur among individuals, groups, and nations."
Reference: Bonnie Sherman and Ziva Kunda, 1989 study - presented students with evidence contradicting deeply held beliefs, and evidence that supported the same beliefs. The students tended to overlook the first and accentuate the value of the second.
Reference: John Darley and Paul Gross - subjects watching a video of a child taking a test - some told the child was from high socioeconomic status, others that the child was from a low socioeconomic status. The subjects were asked to interpret the abilities of the child based on the results of the test. Those told the child were of high status rated the abilities of the child higher than those told the child was of lower status - the same data was interpreted differently based on what the subjects expectations were.
Insight: People that have high internal locus of control believe they are in control and make things happen. People that have high external locus of control believe things are outside their control.
Insight: External locus of control leads to greater anxiety. Internal locus of control makes people more confident, and skeptical of authority.
Reference: 1983 study by Jerome Tobacyk and Gary Milford: people with a high external locus of control are more prone to believing in witchcraft, spiritualism, and superstition.
Example: Rats pressing a lever and being rewarded with food, or humans playing slot machines.
Insight: Reinforcement of behaviour only requires an occasional hit of positive feedback.
