Week 8: Reasoning & Decision making

Question 1

What is reasoning?

Answer 1

The action of thinking about something in a logical (or rational) way to make a decision
– Use our existing knowledge to draw conclusions, make predictions, or construct explanations

• LOGICAL REASONING
• INFORMAL REASONING

Question 2

2 types of logical reasoning:

Answer 2

1. inductive
2. deductive

Question 3

Inductive reasoning

Answer 3

Making broad generalisations from specific observations

• reinforcement is essential

(may not always be true) e.g. dog believes he goes for a walk every day. this is reinforced. However, if the owner had a fall this can change

Question 4

Deductive reasoning

Answer 4

Reaching a specific, logical conclusion from general statements or hypotheses

Typically structured as follows:
i. First premise (or statement) - “P1”
ii. Second premise - “P2”
iii. Inference (or conclusion)

e.g. Jude is taller than Jared (P1)
Jared is taller than Jesse (P2), conclusion = Jude is taller than Jesse

Question 5

Two types of deductive reasoning:

Answer 5

CONDITIONAL

SYLLOGISTIC

Question 6

Deductive reasoning: Conditional

Answer 6

(reasoning with if) – Logical operators included in premises e.g., or, and, if … then, if and only if

Question 6

Deductive reasoning: Syllogistic

Answer 6

– Consists of two premises followed by a conclusion that is either valid or invalid
– Contains three items, with one occurring in both premises
– Premises and conclusions contain quantifiers e.g., all, some, no, some … not

Question 8

Deductive: Conditional reasoning (4 types)

Answer 8

• modus ponens
• modus tollens
• affirmation of the consequent
• denial of the antecedent

Question 9

Modus ponens

Answer 9

• Affirmative

ABAB

If A is true, B is true
A is true
So B is true

VALID

Question 10

Modus tollens

Answer 10

• negative

ABBA

If A is true, B is true
B is not true
So A is not true

VALID

Question 11

Affirmation of the consequent

Answer 11

• affirmative
• ABBA

If A is true, B is true
B is true
So A is true

INVALID

Question 12

Denial of the antecedent

Answer 12

• negative
• ABAB

If A is true, B is true
A is not true
So B is not true

INVALID

Question 13

Deductive reasoning = uninterested reasoning

Answer 13

• Examples of deductive reasoning do not account for:
  – The goals/preferences of an individual
  – An individual’s prior knowledge or expectations
• Contrasts with how we reason in everyday life
  (Also known as informal reasoning)

Question 14

Importance of prior knowledge

Answer 14

Markowitz et al. (2013)

Both conclusions are invalid (affirmation of the consequent)
– But, participants were more likely to accept conclusion to PROBLEM 2 as valid

pps couldn’t think of many other reasons why a finger will be bleeding - however could come up with other reasons why a window could be broken = Importance of context

Question 15

strategy to link to this: Statistical strategy

Answer 15

– Estimate the probability that a conclusion is valid based on what we know about the world
– PROBLEM 2 = higher probability, therefore invalid conclusion accepted

Question 16

Also links: Counterexample strategy

Answer 16

– Try to think of counterexamples that contradict the conclusion
– PROBLEM 2 = more difficult to think of counterexamples, therefore invalid conclusion accepted

Question 17

Which strategy used by pps often depended on…

Answer 17

Time given!!!

Limited time = used STATISTICAL strategy (less cognitively demanding)

Unlimited time = COUNTEREXAMPLE strategy (more cognitively demanding)

Question 18

Deductive reasoning: Syllogistic reasoning

Answer 18

Jude, Jesse and Eden example

- Premises and conclusion contain quantifiers (e.g. some, all, most)

Validity of conclusion depends ONLY on whether it follows logically (validity in real-world is irrelevant)

Question 19

Errors in syllogistic reasoning caused by what bias??

Answer 19

BELIEF BIAS

more likely to…
- accept invalid conclusions if they’re believable
- reject valid conclusions if they’re unbelievable

(end of deductive reasoning)

Question 20

2 theories of logic-based reasoning

Answer 20

1) mental model

2) Dual-systems

Question 21

Mental model

Answer 21

Create a visual image of the problem.

e.g. the lamp is on the right of the pad. the book is on the left of the pad. the clock is infront of the book. the pen is infront of the lamp. So the clock is to the left of the pen

Question 22

Mental model assumptions

Answer 22

• Mental model constructed and conclusions generated
  
  • Construct alternative models to falsify conclusion
    – i.e., counterexamples
  • Reasoning problems that require several mental models are harder to solve
    – Due to increased demands on working memory

Question 22

mental model limitations

Answer 22

• Does not describe how we decide which information to include in a mental model
• Premises
  – Porsche right of Ferrari
  – Mustang front of Porsche
  – Beetle left of Porsche
• Conclusion
  – Beetle left of Ferrari
  No definitive answer - the last premise is ambiguous

Question 23

Dual-systems theories

Answer 23

• Unconscious - heuristic-based process (simplest conclusion asap)
  - Conscious, analytical process (more analytical and time-consuming)

HEURISTIC-ANALYTIC THEORY (evans, 2006)

Question 24

Dual-systems assumptions:

Answer 24

SINGULARITY - one single mental model considered at a time

RELEVANCE - most relevant mental modal considered based on prior knowledge

SATISFYING - Mental model evaluated by analytic system and accepted if adequate

Question 25

INFORMAL reasoning

Answer 25

Refers to the process of everyday reasoning
– Contrasts with the artificial, logic reasoning tasks

	– Is based on knowledge and experience

– Has little to do with formal logic

Question 26

Content: Probabilities

Answer 26

Three factors influence perceived strength of a conclusion:
– Degree of previous conviction or belief
– Positive arguments have more impact than negative arguments
– Strength of the evidence
Hahn & Oaksford (2007)

Question 26

Informal reasoning: Importance of 4 factors

Answer 26

– Content = plausibility

	– Context = expert vs. non-expert

– Probabilities = possibly/probably true

– Motivation = support our viewpoint

Question 27

Context: Neuroscience illusion

Answer 27

• Students provided mixture of “good” and “bad” explanations for psychological phenomena
  – Rate how satisfied they were with each explanation
  
  • Some explanations accompanied by neuroscientific findings

Neuroscientific findings considered more “scientific”
– More complex/expensive equipment
– Assume that information about brain activity provides direct access to information about psychological processes

Question 27

Motivation

Answer 27

• Our judgements can be distorted by our personal goals/beliefs
  – Motivated by our wishes, not facts

MYSIDE BIAS: Tendency to evaluate statements with respect to our belief’s rather than on merit (belief can override facts)

Question 28

Motivation: Climate change

Answer 28

• Tested American’s memories of:
  – Previous summer (been unusually warm)
  – Previous winter (been unusually cold)
  
  • Those most dismissive of global warming: Least likely to remember preceding summer had been warmer than usual