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2. Reasoning
Created @August 21, 2025 1:48 AM
Class PS2021
Reasoning is a process of thought that yields a conclusion from percepts,
thoughts, or assertions
Deductive Reasoning
Deductive reasoning:
Reasoning involves drawing a conclusion from given statements
• The conclusion is based on the assumption that the statements are true.
• If the statements hold, the conclusion logically follows.
Informal Reasoning: A form of reasoning based on one’s relevant knowledge
and experience rather than logic
Conditional Reasoning
Conditional reasoning:
Empirical Studies Testing the Dual
Deductive reasoning using if-
Source Reasoning Model
then propositions
Singmann et al. (2016)
Conditional reasoning problems
Klauer et al. (2010) proposed
a dual-source model of Rating conclusion likelihood on a 0-
conditional reasoning 100% scale
Combines: Results: knowledge-based processes
knowledge-based outweighed form-based ones
process influenced by
premise content
Markovits et al. (2013)
2. Reasoning 1
, form-based process Tested affirmation of the consequent
influenced by logical (invalid conclusion) with examples:
structure
1. If rock thrown → window breaks.
These operate alongside Window broken. Therefore, rock
an intuitive statistical thrown.
strategy using
2. If finger cut → it bleeds. Finger
probabilistic reasoning
bleeding. Therefore, finger was cut.
from relevant knowledge
Using statistical strategy, participants more
often accepted invalid conclusion in problem
2 - higher subjective probability.
Using counterexample strategy,
participants accepted problem 2's
conclusion - fewer counterexamples
conflicting valid conclusion (windows have
many breaking causes).
The model shows counterexample strategy
requires more cognitive effort than
statistical strategy - CS used in 49% of
unlimited-time trials vs only 1.7% with time
limits
Conditional Reasoning Research Evaluation
Limitation Explanation
Research involves
Future research: avoid instructing participants to disregard
instructions indicating
relevant knowledge with CR problems
context is irrelevant
Traditional research
Khemlani and Johnson-Laird (2017)
required participants to
Goals and preferences are ignored as denial of the first part of
draw definite
a statement is not valid in traditional logic
conclusions (true or
I.e., Q is only probably with ONLY P
false)
Wason Selection Task
In a task with four cards (R,
Evaluations of poor performance:
G, 2, 7), each has a letter on
2. Reasoning 2
2. Reasoning
Created @August 21, 2025 1:48 AM
Class PS2021
Reasoning is a process of thought that yields a conclusion from percepts,
thoughts, or assertions
Deductive Reasoning
Deductive reasoning:
Reasoning involves drawing a conclusion from given statements
• The conclusion is based on the assumption that the statements are true.
• If the statements hold, the conclusion logically follows.
Informal Reasoning: A form of reasoning based on one’s relevant knowledge
and experience rather than logic
Conditional Reasoning
Conditional reasoning:
Empirical Studies Testing the Dual
Deductive reasoning using if-
Source Reasoning Model
then propositions
Singmann et al. (2016)
Conditional reasoning problems
Klauer et al. (2010) proposed
a dual-source model of Rating conclusion likelihood on a 0-
conditional reasoning 100% scale
Combines: Results: knowledge-based processes
knowledge-based outweighed form-based ones
process influenced by
premise content
Markovits et al. (2013)
2. Reasoning 1
, form-based process Tested affirmation of the consequent
influenced by logical (invalid conclusion) with examples:
structure
1. If rock thrown → window breaks.
These operate alongside Window broken. Therefore, rock
an intuitive statistical thrown.
strategy using
2. If finger cut → it bleeds. Finger
probabilistic reasoning
bleeding. Therefore, finger was cut.
from relevant knowledge
Using statistical strategy, participants more
often accepted invalid conclusion in problem
2 - higher subjective probability.
Using counterexample strategy,
participants accepted problem 2's
conclusion - fewer counterexamples
conflicting valid conclusion (windows have
many breaking causes).
The model shows counterexample strategy
requires more cognitive effort than
statistical strategy - CS used in 49% of
unlimited-time trials vs only 1.7% with time
limits
Conditional Reasoning Research Evaluation
Limitation Explanation
Research involves
Future research: avoid instructing participants to disregard
instructions indicating
relevant knowledge with CR problems
context is irrelevant
Traditional research
Khemlani and Johnson-Laird (2017)
required participants to
Goals and preferences are ignored as denial of the first part of
draw definite
a statement is not valid in traditional logic
conclusions (true or
I.e., Q is only probably with ONLY P
false)
Wason Selection Task
In a task with four cards (R,
Evaluations of poor performance:
G, 2, 7), each has a letter on
2. Reasoning 2
