lecture 10- deductive and inductive reasoning Flashcards
(25 cards)
what is inductive reasoning?
- drawing general conclusions from particular instances/exmaples
- probably (but not necessarily) true
- e.g extrapolation- can make predictions based on empirical observation
what is hypothesis testing and what type of reasoning is it?
- inductive
- generating general hypothesis based on limited data that can be tested (scientists use)
- aiming to falsify null hypothesis
what is confirmation and falsification?
- confirmation = gain evidence confirming hypothesis is correct (can never fully support it)
- falsification = gain evidence to falsify hypothesis (can prove hypothesis is wrong)
what is Wason’s 2-4-6 task and how does it show confirmation bias?
- given three numbers: 2, 4, 6
- p’s asked to guess rule that generated these numbers
- answer: three numbers in ascending order of magnitude
- bias: guessing ‘goes up in twos’, generating sequences conforming to the sequence, looking for things to confirm what you think is true, and therefore failing to falsify hypothesis
what are the limitations of Wason’s 2-4-6 task?
- not ‘real-world’- immediate feedback doesn’t often occur in the real world, and it’s also never fully informative (not binary ‘correct’ or ‘incorrect’)
- rule is very general, confirmation testing not really appropriate
- confirmation bias not always present (its someone else’s hypothesis)
do scientists always hypothesis test?
- often but not always
- unusualness heuristic- guided by ‘unusual’ results more strongly
- ‘what ifs’- can have hypothesis generation and simulation without experimentation
- theories can end up being modified by discrepant findings (even when acknowledged and methods blamed)
what is deductive reasoning?
- draw definite logical conclusions if tenets are true
- based on formal logic- always right or wrong
- conditional reasoning (logical operators applied to reach conclusions- if P, then Q)
what are antecedents and consequents in conditional reasoning?
- antecedents: if P, then Q and P is true
- consequents: therefore Q
- binary -> either affirm or refute the consequent based on antecedents
what is modus ponens?
if P, then Q -> P therefore Q (correct)
what is modus tollens?
if P, then Q -> not Q therefore not P (correct, but more refute this than modus ponens)
what is irrelevant in conditional reasoning?
real-world knowledge- logic can construct false conclusions (she is in rio, therefore not brazil = FALSE)
we aren’t very good at conditional reasoning- use real-world knowledge (inappropriately)
what did De Neys find about how people engage in conditional reasoning?
- disabler (other reasons for P but not Q) counterexamples decrease acceptance of valid conclusion (modus ponens)
- alternative (other reasons for not P but Q) counterexamples increase correct rejection of invalid conclusions (affirming the consequent)
what is affirming the consequent in terms of P and Q?
if P then Q -> Q therefore P? NO
what is denial of the antecedent?
if P then Q -> not P therefore not Q? NO
why are we more likely to affirm the consequent of some invalid statements more than others (Markovits et al. 2013)
probability of relationship in real world- close/far correspondence between P in Q
what is the Wason selection task?
- four cards on a table- R, G, 2, 7
- each card has a letter on one side, number on the other
- decide if this rule is correct- if R is on one side, the 2 is on the other
- only turn over number of cards needed to decide if rule is true
- answer: turn over R and 7 (R card can confirm rule, 7 card can falsify)
what is informal reasoning?
- reasoning typically found in everyday life
- based on knowledge and experience (unlike formal logic) (like drugs being safe vs. ghosts being real because even though both haven’t been proved wrong)
- own form of reasoning based on probabilities (not bad version of formal)
what is the difference between deductive and informal reasoning?
deductive reasoning- binary (true/false)
informal reasoning- probabilistic (80% chance being correct)
what is the strawman fallacy?
- focusing on weaker points of an opponent’s argument to decrease probability of their view being correct
- your argument becomes relatively more probable (appears more sound)
what is the myside bias in informal reasoning?
evaluate statements with respect to one’s iwn beliefs (evaluaye as more likely to be true when conforms to one’s own beliefs)
what study did Stanovich & West (2007) carry out about the myside bias?
- college students who drink alcohol are more likely to become alcoholic in later life
- students who drank alcohol rate accuracy of this statement lower than those who didn’t drink (don’t want to believe statement is true)
what did Kahan et al. (2012) find about percpetions of climate change?
- best predictor of denial of climate change was cultural values (egalitarian communication vs. hierarchical individualists)
- little to do with actual scientific evidence
what did Howe & Leiserowitz (2013) find about perceptions of climate change?
- those who were dismissive of climate change remembered previous (very hot) summer as colder than those concerned about climate change
- when motivated to deny/have belief of denying -> remember differently
what is bounded rationality?
idea that we are rational, within the limits of our cognitive capacity
- we produce workable solutions to real world problems in spite of limited processing resources
