Task 4 - Reasoning Flashcards
Inductive Reasoning
Making a generalized conclusion from premises referring to particular instances
- > from specific to general
- > conclusions probably but not necessarily true
Deductive Reasoning
Drawing of conclusions from general to specific
- > are definitely valid provided other statements are assumed to be true
- > mostly based on formal logic
Informal Reasoning
Everyday reasoning:
- inductive rather than deductive
- analogical reasoning: solving a problem retrieving information that lead to success in past
Confirmation
Attempt to find supportive or confirming evidence for one’s hypothesis
Falsification
Proposing hypotheses and then trying to falsify them by experimental testing
-> subject to confirmation bias
Positive testing
Numbers used are instances of your hypothesis
- > used to check whether hypothesis is valid (if it isn’t it won’t work)
- > more likely to lead to falsification of hypothesis than negative testing
Negative testing
Numbers used do not conform to your hypothesis
-> if the set of numbers don’t work it confirms your hypothesis
Conditional Reasoning
"reasoning with if" consists of propositions if P then Q: If it is raining, Nancy gets wet -modus ponens -modus tollens
Modus ponens
if A, then B; given A we can validly infer B;
e. g. if it is raining, Nancy gets wet,
- > correct
Modus tollens
when “If A, then B” and premise: “B is false”,
conclusion: “A is false”
e. g. if it is raining, Nancy gets wet, Nancy is not wet , therefore it is not raining
- > correct
Denial of the antecedent
Invalid deductive reasoning: e.g.: if you are a ski instructor, you have a job -> you are not a ski instructor -> therefore you don't have a job false assumption of modus tollens
Affirmation of the consequent
Invalid deductive reasoning.
E.g.: if Bill Gates owns Fort Knox he is rich,
Bill Gates is rich, therefore he owns Fort Knox
-> false assumption of modus ponens
Two System Theory
System 1: pragmatic and semantic strategy,
System 2:
Inhibitory and Generatitive strategy
Pragmatic Strategy
System 1
processing problems as they would be processed informally during a conversation
-associated with numerous error
Semantic Strategy
System 1
- making use of background knoweldge but not of the form of argument in the problem
- associated with moderate performance
Inhibitory Strategy
System 2
Inhibiting the impact of the pragmatic strategy and background knowledge on performance
-works well with some problems
Generative Strategy
System 2
- combining inhibitory strategy with use of abstract analytical processing
- consistently good performance on all types of problems
Wason Selection Task
Often used to test deductive-reasoning -conditional rule used 4 cards lie on table, each has letter on one side and number on other, told that rule applies to all cards e.g.: R, G, 2, 7 which cards need to be turned -> R on one side means two on other side, R and 7 need to be checked -> R: modus ponens -> 7: modus tollens -> 2: affirmation of the consequent -> G: denial of the antecedent
Matching Bias
Tendency for participants to choose items matching those explicitly named in the rule (regardless of whether the matched items are correct)
e.g. on Wason Selection Task
Social Contract Theory
Proposes that problems using deontic rules leads to better performance by people since they are more similar to what people have to deal with in everyday life
-> better with deontic than indiciative rules: directs peoples attention to importance of disproving the rule rather than just finding evidence consistent with it
Deontic Rules
Rules concerned with detection of rule violation;
typically easier to understand for people because the underlying structure of the problem is easier to understand for people
-better task performance than with indicative rules
Syllogistic Reasoning
Logical argument consisting of two premises and a conclusion
- validity depends on whether it follows logically from premises
e. g. all children are obedient, all girl guides are children - > all girls are obedient, conclusion logically from premises
Belief Bias
Error in syllogistic reasoning;
tendency to accept invalid conclusions that are believable and reject valid conclusions that seem unbelievable
Theories of Deductive Reasoning
Mental Model Theory
Dual Systems Theory
Mental Model Theory
People use information contained in premises to construct mental model
- > representation of possible state-of-affairs in the real world
- > valid: we cannot constuct a mental model inconsistent with the conclusion (counterexamples accepted)
- > limited through working memory capacities (highly demanding)
Principle of Truth
Mental model notion that we represent assertions by constructing mental models by what is true but not what is false
Mental Model Theory limitations
People engage in deductive reasoning less than assumed
- ignores individual differences,
- processes of mental model formation under-specified
Dual Systems Theory
System 1: -unconscious processes, emerged at early stage of evolution -involves parallel processing -independent of general intelligence System 2: -conscious processes, recently evolved -rule-based, serial processing -limited capacity (demands more) -cognitive processes evaluating mental models -> better reasoning performance
Principles of human reasoning
Singularity principle
Relevance principle
Satisficing principle
-> explain most errors made by human reasoning
Singularity principle
Only a single mental model is considered at any given time
Relevance principle
Most relevant mental model based on prior knowledge and current context is considered
Satisficing principle
current mental model evaluated by analytic system and accepted if adequate
-> often leads people to accept conclusions that could be true but aren’t necessarily
Brain Systems in thinking and reasoning
Prefrontal cortex
- > right dorsolateral PFC: plan generation
- > left dorsolateral PFC: plan execution
Brain system inductive/deductive reasoning
Activation in left lateral prefrontal cortex, and bilateral dorsal frontal, parietal, and occipital areas
Dual systems support
Reasoning Fallacies
Appeal to popularity Argument from ignorance False cause Irrelevance Begging the question Slippery slope
Appeal to popularity
Argues for claim purely because other people (without clear expertise) accept it
-> Fallacy
Argument from ignorance
Fallacy that since we don’t have any evidence against some claim, it must be true
False cause
Argues that there is correlation between two things and then concludes on that basis, that cause and effect has been shown
-> Fallacy
Irrelevance
Attempts to support claims by way of reason not relevant to the claim
-> fallacys
Begging the question
Assume as a premise what it claims to be proving. Seeking to support a conclusion by appealing to the same conclusion
-> fallacy
Slippery slope
Claims that innocent-looking first step will lead to bad consequences but doesn’t prove how or why one will lead to the other
Analytical Thinking and Religious Disbelief
Analytical thinking promotes religious disbelief
Mortality salience and analytic thinking
Mortality salience impairs analytic thinking
-> executive resources might be mobilized to suppress death thoughts
