Belief bias
Encyclopedia
Belief bias is a cognitive bias
in which someone's evaluation of the logical strength of an argument
is biased by their belief
in the truth or falsity of the conclusion. This effect has been demonstrated in psychological experiments, and is independent of reasoning ability.
In a series of experiments by Evans, et al., subjects were presented with deductive arguments
(in each of which a series of premises and a conclusion are given) and asked to indicate if each conclusion necessarily follows from the premises given. In other words, the subjects are asked to make an evaluation of logical validity
. The subjects, however, exhibited belief bias when they rejected valid arguments with unbelievable conclusions, and endorsed invalid arguments with believable conclusions. It seems that instead of following directions and assessing logical validity, the subjects based their assessments on personal beliefs.
Further tests using fMRI scans showed differential cerebral activation between belief-neutral trials, or syllogisms involving obscure terms of which the participants were unaware, and belief-laden trials, or syllogisms that could be influenced by knowledge affecting the believability of conclusions. In the belief-neutral trials, activation was seen in the upper parietal lobe, a region involved in mathematical reasoning and spatial representation. In the belief-laden trials, the additional activation of the front left temporal lobe was observed, a region involved in the retrieval and selecting of facts from long-term memory. This indicated that in belief-laden reasoning, people also drew upon memory in addition to abstract reasoning.
It has been argued that like in the case of the matching bias, using more realistic content in syllogisms can facilitate more normative performance, and the use of more abstract, artificial content has a biasing effect on performance.
Cognitive bias
A cognitive bias is a pattern of deviation in judgment that occurs in particular situations. Implicit in the concept of a "pattern of deviation" is a standard of comparison; this may be the judgment of people outside those particular situations, or may be a set of independently verifiable...
in which someone's evaluation of the logical strength of an argument
Argument
In philosophy and logic, an argument is an attempt to persuade someone of something, or give evidence or reasons for accepting a particular conclusion.Argument may also refer to:-Mathematics and computer science:...
is biased by their belief
Belief
Belief is the psychological state in which an individual holds a proposition or premise to be true.-Belief, knowledge and epistemology:The terms belief and knowledge are used differently in philosophy....
in the truth or falsity of the conclusion. This effect has been demonstrated in psychological experiments, and is independent of reasoning ability.
In a series of experiments by Evans, et al., subjects were presented with deductive arguments
Deductive reasoning
Deductive reasoning, also called deductive logic, is reasoning which constructs or evaluates deductive arguments. Deductive arguments are attempts to show that a conclusion necessarily follows from a set of premises or hypothesis...
(in each of which a series of premises and a conclusion are given) and asked to indicate if each conclusion necessarily follows from the premises given. In other words, the subjects are asked to make an evaluation of logical validity
Validity
In logic, argument is valid if and only if its conclusion is entailed by its premises, a formula is valid if and only if it is true under every interpretation, and an argument form is valid if and only if every argument of that logical form is valid....
. The subjects, however, exhibited belief bias when they rejected valid arguments with unbelievable conclusions, and endorsed invalid arguments with believable conclusions. It seems that instead of following directions and assessing logical validity, the subjects based their assessments on personal beliefs.
Further tests using fMRI scans showed differential cerebral activation between belief-neutral trials, or syllogisms involving obscure terms of which the participants were unaware, and belief-laden trials, or syllogisms that could be influenced by knowledge affecting the believability of conclusions. In the belief-neutral trials, activation was seen in the upper parietal lobe, a region involved in mathematical reasoning and spatial representation. In the belief-laden trials, the additional activation of the front left temporal lobe was observed, a region involved in the retrieval and selecting of facts from long-term memory. This indicated that in belief-laden reasoning, people also drew upon memory in addition to abstract reasoning.
It has been argued that like in the case of the matching bias, using more realistic content in syllogisms can facilitate more normative performance, and the use of more abstract, artificial content has a biasing effect on performance.