The Psychology of Proof and Choice Flashcards
What is Proof
Evidence or argument establishing a fact of the truth of a statement = drawing an inference
Types of inference
Deduction (specific inference)
Induction (General inference)
Abduction (Best explanation available)
How does the mind undertake deduction
Structure
Semantics
Statistics
Inference as logical reasoning
Assumption: Individuals draw conclusions from premises by applying stored rules of logic to derive a single valid inference
Types of inference
Classical syllogisms: A are B some B are C so therefore C are A
Condition inferences: If i do A then i get B if i didn’t get B then i didn’t do A.
Transitive inferences: J is fast than M, J is slower than B, therefore B is faster than M and J.
Conditional Syllogisms
If x is a mammal then x is an animal
Minor premises - potential conclusions
The structural view
Formal logic - the used of syntactic structure to determine the validity of an argument
Braine and O’Brien - natural deduction
Direct inferences
Indirect inferences
Bayes Rule
P(H/D) = p(D/H) x p(H) over [p(D/H) x p(H)] + p (D/notH) x p (not H)}
Information gain
Information: reduction in uncertainty
Reasoning is about expected information gain (what if)
Types of Choice
Normative/ prescriptive models
“rational” = selecting opitmally
Expected value : highest resource value = objective value x probability
Expected utility: highest psychological value = subjective utility x probability
Prospect theory
Model -
Editing: selecting desired outcomes against a reference point via heuristics
Evaluation: value judgement based on calculation of anticipated utilities x probabilities
Loss aversion-
Faced with risky choice leading to gains, individuals are risk-averse
Faced with a risky choice of leading to losses, individuals are risk seeking
Probability weighting
People attribute excessive weight to events with low probabilities and insufficient weight to events with high probability
Heurisitcs and biases
Representativeness - conjunction fallacy
Anchoring
Hypothesis testing and pseudodiagnosticity
belief that more information about current hypothesis is the most diagnostic choice
testing prospect theory
Prospect theory explains preference reversal as - loss aversion - choosing low number gives a perceived greater certainty of gain, but selling a high number gives a greater perceived risk of loss
Anchoring- precise numbers determine the degree to which people value the utility of each bet
