Reasoning and Decision Making Quiz

Reasoning & Decision Making

• Reasoning is a cognitive process where individuals start with information and draw conclusions that go beyond the initial information.
• Reasoning can involve heuristics, which are mental shortcuts.
• Two types of reasoning: deductive and inductive.

Deductive Reasoning

• Deductive reasoning starts with a general statement or premise and leads to a specific, logical conclusion.
• The basic form of deductive reasoning is a syllogism.
• A syllogism consists of two premises (statements assumed to be true) and a conclusion drawn from these premises.
• Example: Premise 1: All cats are mammals. Premise 2: All mammals are animals. Conclusion: All cats are animals.
• Syllogisms can be evaluated using a normative approach, focusing on logical validity, or a descriptive approach, focusing on how people actually reason.

Deductive Reasoning: Syllogisms

• Normative approach focuses on whether syllogisms are logically valid, based on formal rules of logic.
• Example using a normative syllogism: Premise 1: All dogs are animals. Premise 2: All animals have cells. Conclusion: Therefore all dogs have cells.
• Descriptive approach looks at how people evaluate syllogisms in practice.
• Example using descriptive approach: Premise 1: All birds can fly. Premise 2: Penguins are birds. Conclusion: Therefore penguins can fly.

Invalid Syllogisms

• Invalid syllogisms (normative): Premises may be true, but conclusion does not follow logically..
  • Example: Premise 1: All cats are mammals. Premise 2: All dogs are mammals. Conclusion: Therefore, all cats are dogs.
• Invalid syllogisms (descriptive): Errors happen due to misapplications of common beliefs that don't logically lead to the conclusion.
  • Example: Premise 1: some people who exercise are healthy. Premise 2: John exercises. Conclusion: Therefore, John is healthy.

Inductive Reasoning

• Inductive reasoning starts with specific observations or evidence and leads to a general conclusion that is probably true.
• Example: The sun has risen every day so far, therefore, the sun will rise tomorrow.

Heuristics and Inductive Reasoning

• Heuristics (mental shortcuts) can lead to errors in reasoning. Common errors in inductive reasoning are
• Availability Heuristic
• Illusory Correlations
• Representative Heuristic
• Confirmation Bias

Availability Heuristic

• Judging the likelihood of an event based on how easily examples come to mind.
• Example: After buying a particular brand of smartphone, you start noticing it everywhere, even though it's not actually more common than other products.

Illusory Correlations

• Perceiving a relationship between two variables where no relationship actually exists.
• Example: Believing that wearing a lucky shirt always makes your team win a game.

Representative Heuristic

• Judging the probability of an event based on how similar it is to a prototype or stereotype.
• Example: Assuming someone who wears glasses always studies.

Confirmation Bias

• Prioritizing information that confirms existing beliefs and disregarding information that contradicts them.
• Example: believing a certain diet is effective and focusing on examples supporting that belief, while ignoring examples of cases where it failed.

Reasoning and the Brain

• Prefrontal cortex plays a key role in reasoning, problem-solving, and working memory.

Inductive vs. Deductive Reasoning Summary

• Deductive reasoning derives logically sound conclusions from established premises.
• Inductive reasoning generates generalized conclusions from specific observations.