Reasoning Judgments and Decision Making Flashcards
What are the 2 thought processes behind reasoning?
- syllogisms
2. conditional reasoning
What is a syllogism?
A syllogism is a logical argument that applies deductive reasoning to arrive at a conclusion based on 2+ propositions that are assumed to be true.
Syllogism = 2 premises’ + conclusion
Give an example of a syllogism:
Premise 1 (P1): All men are mortal.
Premise 2 (P2): Socrates is a man.
Conclusion (C): Therefore, Socrates is mortal.
To be true, a syllogism must be _____ (i.e., be logical) and ____.
To be true, a syllogism must be valid (i.e., be logical) and true.
Validity vs. Truth
To solve a syllogism, it is first necessary to evaluate its:
1.
2.
- Validity
- Truth of its premises.
Example:
P1: All apples are fruit.
P2: All fruit can swim.
C: Therefore, apples can swim.
The above example is a valid argument, but it is not true because the second premise is false.
To be true, an argument must be ____ and both premises must be ____.
To be true, an argument must be valid and both premises must be true.
What are the 2 basic heuristics (i.e., strategies) for solving syllogisms?
- Venn diagrams.
2. Making abstract syllogisms more concrete.
What is a venn diagram?
Diagrams showing relationships among sets of things.
How do you make abstract syllogisms more concrete?
By replacing abstract things with more concrete ones
Example:
P1: All As are Bs.
P2: All Bs are Cs.
C: Therefore, All As are Cs.
What is confirmation bias?
The tendency when reasoning to look for examples that confirm the truth of some argument.
Why are counter-examples essential to confirm truthfulness when critically evaluating syllogisms?
Because they help us avoid confirmation bias, by making us seek examples the do not conform to our preconceived notions.
According to Helsabeck (1975), how can people’s performance solving syllogisms be improved with training?
They are explicitly taught to avoid confirmation bias by looking for counter examples.
What is conditional reasoning?
Conditional reasoning involves evaluating the truth of a 2-part statement that specifies some relationship between 2 assertions.
Example
If it’s raining, then I’m carrying my umbrella.
It’s raining.
(Conclusion: Am I carrying my umbrella?)
What are the 4 possible outcomes of conditional reasoning?
- Affirming the cause.
- Denying the cause.
- Affirming the effect.
- Denying the effect.
In conditional reasoning, what is affirming the cause, and is it a valid argument?
P implies Q
Evidence: It’s raining (p).
Conclusion? I’m carrying my umbrella (q).
It is a valid argument.
