Deductive Reasoning and Arguments

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Questions and Answers

What components make up an argument?

A proposition and its evidence

Observations and interpretations

Reasons for a claim and the final claim (correct)

A sequence of premises and conclusions

Which statement is an example of deductive reasoning?

All cats are mammals. My pet is a cat. Therefore, my pet is a mammal. (correct)

All dogs bark. My friend’s dog barks. Therefore, it is a dog.

Some fish are colorful. Goldfish are colorful. Therefore, goldfish are rare.

Some birds can swim. Penguins are birds. Therefore, penguins swim.

What does 'deductive validity' imply?

It is impossible for the conclusion to be false if the premises are true. (correct)

The conclusion must be plausible based on common beliefs.

The argument is only valid if it includes multiple premises.

The premises do not have to relate directly to the conclusion.

What is the 'belief bias' phenomenon?

Judging logically invalid conclusions as valid if they seem plausible. (C) Signup and view all the answers

In the syllogism 'All humans are mortal. Aristotle is human. Therefore, Aristotle is mortal', what role does 'Aristotle is human' play?

A premise (B) Signup and view all the answers

What effect does the number of logical rules in an argument have?

It increases the likelihood of making mistakes. (A) Signup and view all the answers

Which statement best describes the relationship between premises and conclusions in deductive reasoning?

The conclusion must logically follow from the premises. (D) Signup and view all the answers

If a statement is made that 'No addictive things are inexpensive' and 'Some cigarettes are inexpensive', which conclusion can be logically derived?

Addictive things must all be expensive. (B) Signup and view all the answers

What is an example of the representativeness heuristic?

Evaluating a situation based on its similarity to a stereotype you hold. (A) Signup and view all the answers

Which statement best describes confirmation bias?

Favoring evidence that reinforces existing beliefs over contradictory evidence. (A) Signup and view all the answers

What is the main difference between deductive and inductive reasoning?

Deductive reasoning guarantees true conclusions if premises are true, while inductive reasoning involves likelihood. (C) Signup and view all the answers

How does framing effects influence decision making?

It alters perceptions based on how information is presented. (A) Signup and view all the answers

Which of the following statements is correct about belief bias?

It causes people to favor their beliefs even if they contradict logical reasoning. (D) Signup and view all the answers

Which scenario would likely exhibit confirmation bias?

Seeking out articles that align with one's view on a controversial issue. (B) Signup and view all the answers

What is the primary role of heuristics in inductive reasoning?

To simplify decision making by providing quick estimations. (D) Signup and view all the answers

Why is inductive reasoning described as involving 'likelihood' rather than 'certainty'?

It involves making generalizations based on specific observations. (D) Signup and view all the answers

What does the content of a problem influence in deductive reasoning?

The rules that are applied for evaluation (B) Signup and view all the answers

Which of the following best describes pragmatic rules?

Rules that depend on the content of a situation (B) Signup and view all the answers

Which reasoning method begins with specific premises to form a general conclusion?

Inductive reasoning (B) Signup and view all the answers

In Linda’s problem, which statement represents inductive reasoning?

Given her traits, it is probable that Linda is a bank clerk. (A) Signup and view all the answers

What commonality do pragmatic rules and mental models share?

Both are influenced by the content of the problem (D) Signup and view all the answers

Which statement is true about inductive strength?

It relies on the probabilities derived from the premises. (D) Signup and view all the answers

In the Wason Selection Task, which cards would you need to turn over to confirm the conditional statement?

The vowel card and an odd number card (D) Signup and view all the answers

What differentiates deductive reasoning from inductive reasoning?

Inductive reasoning may result in conclusions that are not certain. (B) Signup and view all the answers

Study Notes

Thought- Reasoning

A sequence of thoughts is organized in a proposition.
An argument is a proposition that includes reasons (premises) for a claim (conclusion).
The claim can report on the certainty or probability of a fact.

Different Reasoning Goals

Deductive Reasoning: Aims for certainty.
Inductive Reasoning: Aims for probability.

Deductive Reasoning Examples

Example 1:
- No addictive things are inexpensive.
- Some cigarettes are inexpensive.
- Therefore, some addictive things are cigarettes.
Example 2:
- No addictive things are inexpensive.
- Some cigarettes are inexpensive.
- Therefore, some cigarettes are not addictive.

Syllogism Example

All humans are mortal.
Aristotle is human.
Therefore, Aristotle is mortal.
Unicorns don't fly.
I don't fly.
Therefore, I am a unicorn. (Note: this is a flawed example).

Deductive Reasoning: Logical Rules

Deductive validity: If premises are true, the conclusion cannot be false.
Example: Penguins are black and white. Some old TV shows are black and white. Therefore, some penguins are old TV shows. (Note: this is a flawed example).

Deductive Reasoning: Difficulty and Errors

The more rules an argument requires, the harder it is and the more likely errors will be made.
People take longer to make correct decisions with more complex arguments.

Deductive Reasoning: Effects of Content

Belief Bias: People often judge a logically invalid conclusion as valid if it seems plausible.
Content of propositions affect the rules used.
Pragmatic rules, less abstract but relevant to everyday problems.
Mental models help to represent situations.

Wason Selection Task

If a card has a vowel on one side, it has an even number on the other side.
Which cards would you turn over to determine if the claim is correct? (E, K, 2, 7)

Pragmatic Rules Example

If a person is drinking beer, he/she must be over 18.
Cards: BEER, COKE, 22, 16
The content of a problem affects whether a pragmatic rule is activated.

Deductive Reasoning: Content Sensitivity

Applying pragmatic rules and creating mental models depend on the problem's content.

Inductive Reasoning Example

Sam qualified in accounting at college.
Sam now works for an accounting company.
Therefore, Sam is an accountant.

Deductive vs. Inductive Reasoning

Deductive reasoning uses general premises to form a specific conclusion.
Inductive reasoning uses specific premises to form a general conclusion.
Inductive reasoning generates hypotheses (not certainties).
Inductive strength is about probability.

Linda's Problem (Kahneman & Tversky)

Linda is 31, single, outspoken, bright, majored in philosophy, concerned with discrimination.
Estimate probabilities: Linda is a bank clerk; Linda is a bank clerk and active in the feminist movement.

Inductive Reasoning: Probability Rules

Base-rate rule: The probability of something being in a class is higher if there are more members in that class.
Conjunction rule: Probability of a proposition cannot be less than the probability of that proposition combined with another proposition.

Inductive Reasoning: Heuristics

Heuristics are mental shortcuts that are easy to apply but not always reliable.
People use heuristics in everyday life.

Inductive Reasoning: Tversky & Kahneman

Tversky and Kahneman showed that people often violate basic probability theory when making inductive judgments.

Daniel Kahneman

Nobel Prize winner for behavioral economics research.
Integrated psychological insights into economic science.
Research on human judgment and decision-making under uncertainty.

Inductive Reasoning: Similarity Heuristic

People base judgments on the similarity between current situations and prototypes or stereotypes.

Inductive Reasoning: Availability Heuristic

People base judgments on information that readily comes to mind.

Inductive Reasoning: Causality Heuristic

People estimate the probability of a situation based on the strength of the causal connections between events.

Reasoning and Decision Making: Effects and Biases

Framing effects: The way information is structured can influence decisions.
Belief bias: Abandoning logical rules in favor of personal beliefs.
Confirmation bias: Favoring evidence that confirms existing beliefs.

Neural Basis of Reasoning

Different parts of the brain are activated during deductive and inductive reasoning.

Reasoning at a Glance: Deductive Thinking

Start with general principles.
Assess if they fit the specific case.
Conclude on the specific case.

Reasoning at a Glance: Inductive Thinking

Start with specific facts.
Formulate a general principle.
Collect and evaluate facts.

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Description

Explore the fundamentals of deductive reasoning, its goals, and how to construct logical arguments. This quiz includes examples of syllogisms and various reasoning methods to enhance your understanding of logical validity. Test your skills in identifying premises and conclusions in different scenarios.