Task 4 - Reasoning

Question 1

Deductive & Inductive Reasoning

Answer 1

INDUCTIVE REASONING
=making generalized conclusions from premises referring to particular instance
probable, but not necessarily true - generalization provides no certainty
scientists often make use of it
-Analogical reasoning: solve current problem by retireving information about similar, already solved problem
-Hypothesis testing: difference between confirmation & falsification

DEDUCTIVE REASONING
=drawing definitely valid conclusions assumed other statements are true
related to problem solving - definitive goal, but no obvious solutions
based on formal logic
-Conditional reasoning: “if p, then q”, based on conditional propositions
-Syllogistic reasoning: arriving at a conclusion based on two or more propositions assumed to be true

Question 2

Rules of Interference & Explanations

Answer 2

MODUS PONES (IMPLICATION ELIMINATION)
valid logical reasoning
If “P then Q” is given, we can validly infer q
100& of people made valid modus ponens inference
Influence of context - additional arguments lead to reduction in perormance

MODUS TOLLENDS (DENYING THE CONSEQUENT)
valid logical reasoning, but often regarded as invalid by individuals
If “p, then Q” and “Q is false” the conclusion “P is false” necessarily follows
less than 60% of people made valid modus tollends inference
Influence of context

DENIAL OF ANTECEDENT (INVERSE ERROR OR FALLACY OF THE INVERSE)
invalid logical reasoning
formal fallace of infering the inverse from the original statement

AFFIRMATION OF CONSEQUENT (CONVERSE ERROR OR FALLACY OF THE INVERSE)
invlaid logical reasoning - confusion of necessity and sufficiency
formal fallacy of taking a conditional statement and invalidly inferring its converse
Arises when Q has one more other P
A little more commonly accepted than denial of antecedent

Question 3

Theories of deductive reasoning

Answer 3

MENTAL MODEL THEORY
=individuals carrying out a reasoning task contruct one or more mental models: representations of a possibility of the state-of-affairs in the world. People use deductive reasoning which may be affected by real-world knowledge
-Principle of truth: individuals minize load on working memory by constructing mental models representing what is true / false
-Iconic in that their structure corresponds to what they represent
-Illusory inferences: error that occur when people adhere to the principle of truth (fail to think about what is false)

Limitations:

1. assumes people engage in deductive reasoning is greater than actually true
2. processes involved in forming mental models are underspecified
3. ignores individual differences
4. assumes that people will try to produce mental models that falsify conclusions generated from their initial mental model
5. increasing evidence shows two different processing systems are used for reasoning

DUAL-SYSTEM THEORIES
=people use knowledge and immediate context in reasoning, which may be affected by deductive reasoning by the analytic system
-System 1: involves unconscious processes, emerged at early stage of evolution, involves parallel processing, independent of general intelligence
-System 2: conscious processes, rule-based serial processing, limited capacity, linked to general intelligence
-Heuristic analytic theory

• Human reasoning is based on 3 principles:
  1. Singularity (single mental model considered at given time)
  2. Relevance (most relevant mental model is considered)
  3. Satisfying (current mental model evaluated by analytic system and accepted if adequate, conclusions not necessarily true)

Limitations:

1. oversimplification
2. assumed that there are several different kinds of analytic processes which vary, unclear how individuals decide which to use
3. assumed that heuristic and analytic processes interact & compete for behavior control

Question 4

Informal reasoning

Answer 4

= a form of reasoning based on one’s relevant knowledge and experience rather than logic

more important in everyday life than deductive reasoning
Better to study directly
knowledge and experience are often used to argue persuasively for/against some statement –> little to do with logic
content of an argument is generally important

BAYESIAN APPROACH based on assumption that prior subjective probabilities are modified by new information provides a very useful framework within which to understand infromal reasoning
Limitations: too flexible, hard to falsify, little has been discovered about individual differences

Question 5

Rationalism in humans

Answer 5

Humans are not very rational if we define rationality as reasoning according to rules or logic
Humans rationality involves effective use of probabilities rather than logic

WHY HUMAN REASONING IS NOT LIMITED
Performance on tasks is often poor because its unclear which information is important
decision people make often influenced by accountability (need to justify decisions)
errors on deductive reasoning problems often mostly reflect the artificiality of such problem
Performance on many judgement and reasoning tasks underestimates people’s ability to think effectively

WHY HUMAN REASONING IS LIMITED
poor motivation not responsible for low levels of performance
poor performance sometimes due to limitation within participants
many participants fail to solve problems even when strenuous steps are taken
we would expect experts ton interpret problems correclty –> infact, medical experts make biased judgements and decisions
-Dunning kruger effect - the finding that less skilled individuals overestimate their abilities more than those who are more skilled