Types of Deductive Reasoning
Conditional (propositional) reasoning
Relationship between 2 conditions
Proposition
statement you are making the
decision about.
What is people handle positive information better than negative information
– Take longer
– More errors
Other aspects of Conditional (propositional) reasoning
- If.....then
- Judged as valid or invalid
Affirm
concluding the statement is
true/valid.
Examples of people handle positive information better than negative information
Example:
– If today is not Friday, then we will not have a quiz
today.
– We will not have a quiz today; therefore, today is not
Friday.
Syllogism
2 statements that we must assume to be true, plus a conclusion.
Deny
confirm the statement is false/invalid.
Affirmed the consequent – invalid!
May seem like you are denying the consequent
Examples of Syllogism
- Some psychology majors are friendly people.
- Some friendly people are concerned about poverty
Antecedent
If statement, comes first.
Abstract Reasoning Problems
People also struggle with reasoning problems that
involve abstract vs. concrete examples
Examples of Conditional (propositional) reasoning
If a child is allergic to peanuts, then eating peanuts
produces a breathing problem.
– A child has a breathing problem.
– Therefore, this child has eaten peanuts.
Consequent
Consequence, comes second
– The “then” part is true
Examples of Abstract Reasoning Problems
– If an object has polka dots, then it is spherical
– The object is not spherical, therefore it does not have polka dots