Lecture 9 - Reasoning 1

Question 1

what is conditional reasoning

Answer 1

How the words in connecting propositions (‘connectives’) influence inferential reasoning
Affect drawing correct conclusions based on making inferences (going beyond evidence)
‘Connectives’: words such as ‘if’, ‘or’, ‘not’
Propositions typically of ‘if-then’ form
Typically comprise 1 premise (with 2 parts), 1 statement of (factual) information and 1 conclusion
Propositions logically-correct (valid) if conclusion follows logically from premise given information statement

Question 2

what is a connective

Answer 2

• words such as if/ then

Question 3

what part is the anticdent

Answer 3

if

Question 4

what is the consequent

Answer 4

then

Question 5

what is the factual information

Answer 5

imformation given in tasks

Question 6

what is the conclusions

Answer 6

• whether something is valid/ invalid

if logical

Question 7

what are the 4 different types of interferances

Answer 7

2 logically vaid:
modus pollens
modus tollens

2 logically invalid
affirmation of consequent
denial of antecedant

Question 8

what does Modus pollen do

Answer 8

logically-valid (comply with principles of logic):
Modus ponens (MP)
Or: Affirmation of antecedent
- agreement with - agreeing with If part

Question 9

what is Modus tollens (MT)

Answer 9

Modus tollens (MT)
Or: Denial of consequent
going against then part

denying the then part

Question 10

what is Affirmation of consequent (AC)

Answer 10

agreeing with if part
Drawing logically-incorrect conclusion from premises

logicaly incorrect as - eg you ar eout of the house therefore you are cheating on me- agreeing with then part but could be out of the house for other reasons

Question 11

what is Denial of antecedent (DA)

Answer 11

agreing with then part

Logically-invalid (fallacious) because:
Although first part (antecedent) of premise false (not P), it doesn’t mean that it’s logical to infer that its second part (consequent) of premise also false (not Q)
e.g., logically-incorrect to infer that because you’re not a socialist you’re not in favour of welfare state
e.g., you could be a benevolent/caring capitalist who believes that all people (regardless of income/wealth) are entitled to avail of free healthcare

because if the first bit is false doenst mean second bit is false

info illogically valid

Question 12

what are the results by the Study by Evans, Handley and Buck (1998)

Answer 12

Study by Evans, Handley and Buck (1998)
Results:
Denial of the antecedent (DA): endorsed by 59% of participants
Affirmation of the consequent (AC): endorsed by 77% of participants
Modus ponens (MP): endorsed by 98% of Ps
Modus tollens (MT): endorsed by 60% of Ps

Question 13

Why is logical reasoning worse for MT logical inference than MP inference?

Answer 13

DUE TO NEGATION (not)

Basically, presence of negation in information statement of MT inference
e.g., There is not a dialling tone

have to think of alternatives- take cognitive resources

Two theoretical accounts:
Mental rules
Mental models

Question 14

why does negation make thing difficult

Answer 14

Basically, presence of negation in information statement of MT inference
e.g., There is not a dialling tone

have to think of alternatives- take cognitive resources

Two theoretical accounts:
Mental rules
Mental models

Question 15

what are the 2 theoretical accounts of negtation

Answer 15

Mental rules

Mental models

Question 16

Describe the mental rules theory

Answer 16

More rules involved in modus tollens
Modus tollens:
Have to deconstruct modus ponens version of argument (‘if P then Q’) before analysing modus tollens version of argument (‘if P then not-Q’)
Rules:
Assume ‘if P’ true (modus ponens)
Assume ‘then Q’ true (modus ponens)
Consider information supporting information statement
(‘Q’) and opposite to info statement (‘not-Q’)
Generate conclusion based on analysis of information statement

Question 17

what assumption are made by the Mental models theory (Johnson-Laird, 1983

Answer 17

Procedures for manipulating mental representations
Mind contains no ‘mental logic’ (mental rules)

Models constructed to interpret/understand premise

Errors due to failure to keep track of mental models

Question 18

what are the 3 stages made by the made by the Mental models theory (Johnson-Laird, 1983

Answer 18

Comprehension of premise (model construction)
Draw conclusion based on mental models
Search for counter-examples (alternative models where conclusion false)

Question 19

what is the mental models theory

Answer 19

Need to generate more models for modus tollens than modus ponens
Modus tollens:
Need to ‘flesh-out’ basic, modus ponens inference mental model (‘if P then Q’) to draw conclusion
‘Fleshing-out’: basically, generating more complex mental representation of argument
Searching for counter-examples regarding content of information statement and/or conclusion
e.g., other reasons for lack of dialling tone on phone

Question 20

describe fleshing out according to the mental models theory

Answer 20

need to ‘flesh-out’ basic, modus ponens inference mental model (‘if P then Q’) to draw conclusion
‘Fleshing-out’: basically, generating more complex mental representation of argument
Searching for counter-examples regarding content of information statement and/or conclusion
e.g., other reasons for lack of dialling tone on phone