05/06 Beliefs & Reasoning: Logic, Confirmation Bias, Heuristics & Evidence

Tversky & Kahneman (1974) Heuristics and Biases; Pennycook & Thompson (2022) Base-Rate Neglect

Deductive reasoning

Reasoning from premises to logically certain conclusions

Inductive reasoning

Using observations to make probabilistic generalisations

Sound argument

Valid logical structure with true premises

Modus ponens

If P then Q; P; therefore Q

Modus tollens

If P then Q; not Q; therefore not P

Affirming the consequent

If P then Q; Q; therefore P; invalid inference

Denying the antecedent

If P then Q; not P; therefore not Q; invalid inference

Formal fallacy

Error in the logical structure of an argument

Informal fallacy

Flaw in the content or use of information in an argument.

Belief bias

Judging an argument by how believable its conclusion is rather than its logical validity

Confirmation bias

Seeking or interpreting evidence in ways that support existing beliefs

Wason selection task

Logic task testing whether people seek evidence that could falsify a conditional rule

Actively open-minded thinking

Considering alternatives and contradictory evidence before reaching conclusions

Availability heuristic

Judging likelihood by how easily examples come to mind

Representativeness heuristic

Judging probability by similarity to a typical case

Conjunction fallacy

Judging a combination of events as more likely than one event alone

Base-rate neglect

Ignoring general statistical frequencies in favour of specific information

Epistemic rationality

Forming accurate beliefs based on evidence and reasons

Empirical claim

Claim that can be tested using observable evidence

Regression to the mean

Extreme observations tend to be followed by observations closer to the average

Correlation ≠ causation

An association does not establish that one variable causes another

Confound

Variable influencing both the independent and dependent variables

Reverse causation

Assuming X causes Y when Y may actually cause X

Selection bias

Non-random selection produces unrepresentative data

Scientific method

Systematic testing of claims using evidence, experiments, and attempts to falsify hypotheses