Reasoning, Judegement and Decision making Flashcards
what is reasoning
cognitive processes by which people start with information and come to conclusions that go beyond that information
deductive reasoning
any form of reasoning in which the conclusions follow with certainty from the premises
inductive reasoning
any form of reasoning in which the conclusions follow only probabilistically from the premises
syllogisms
logical arguments containing two statements called premises and a third statement called a conclusion
can be valid or invalid
is valid if the conclusion follows logically from its two premises
cateogrical syllogisns
describe the relation between two categories using the terms all no or some eg aristotle's perfect syllogism premise 1 = all a are b premise 2 = all b are c conclusion therefore all a are c
validity vs truth
validity = refers to form
truth = refers to content
but note that if two presmises of a valid syllogism are true, the syllogism’s conclusion must also be true
how well can people judge validity
evaluation = ask people if the conclusion follows logically from the premise
production = ask people to indicate what logically follows from the premise
many errors in evaluation
-belief bias
-atmosphere effect
belief bias
if the syllogisms conclusion is something people already believe to be true, they are more likely to judge the conclusion as following from the preises
atmosphere effect
the logical terms (all, no, some, not) used in the premised of the syllogism bias people to accept conclusions that have the same terms
consitional statements and syllogisms
conditional syllogisms are another form of deductive reasoning
a conditional statemtn has the form if P, then Q
first part = antecedent provides th ocndition under which the second part (consequence) is guaranteed to be tru
in judging the validity of conditional syllogisms how well do people generally do
if p, then q..
affirming the antecende = good
denying the consequent = ok
affirming the consequent = poor
denying the antecedent = poor
wason four card problem
used to test the effect of using real world items in a conditional reasoning problem
-if a card has a vowel on one side, then it must have an even number on the other side
-which cards must be turned over to test this rule
eg EK47
falsification principle
to test a rule, you must look for situations that falsify the rule
most participatns of wason four-card problem fail to do this
when problem is stated in concrete everyday term, correct responses generally increase
how to make wason four-card problem more concrete and waht happend
if a person is drinking beer, then the person must be over 21 years of age
which cards must be turned over to test this rule
when the problem is stated in concrete, everyday terms, correct responses greatly increase
why is the more concrete version of the wason four-card problem easier
a person performance can be greatly enhanced when the material to be judged has meaningful content
two possible explanations for this effect
1 - permission schema
2 - familiarity with the rule
permission schema
evolutionary psychologists suggest people can detect cheaters who are not following rules of social itneraction
-permission schem: if a is satisfied, b can be carried out - used in concrete version: if 21 can drink beer
an alternative explanation is that particiaptns simply have greater familiarity with the rule
can we discriminate between these two explanations?
testing familiarity vs permission
-cosmides and tooby
created unfamiliar situations where cheating could occue
-if a man eats root, he must have tattoo
-participants did well
-evidence against familiarity account
take-home message: cheating (or permission) within context is important, familiarity is not always important
induction in inductive reasoning
a pattern of reasoning in which one seeks to draw general claims from specific bits of evidence
premises are based on observation
we generalise from these cases to braoder conclusionswith varying degrees of certainty
eg based on what you know about cars, which is the best to buy
strength of argument in inductive reasoning
representativeness of observations
number of observations
quality of observations
how we use inductive reasoning
used to make scientific discoveries
-hypotheses and general conclusions
used in everyday life
-make a prediction about what will happen based on observations about what has happened in the past