REASONING

Reasoning: Induction vs. Deduction

  • John Locke (1632-1704):
    • Emphasized the importance of reasoning and logic in discovering truths.
    • Key processes include arranging ideas, perceiving connections, and making decisions.

Deductive Reasoning

  • Definition:
    • A normative approach where conclusions are derived from established axioms or theories.
    • Focuses on evaluating the validity of conclusions.
    • The premise guarantees the conclusion, meaning there is a right answer.
  • Example:
    • Axiom: "Things fall when dropped" (gravity).
    • Conclusion: "My cup will fall if I drop it."
    • Logical structure: If all dogs have ears and Pitbulls are dogs, then Pitbulls have ears.

Inductive Reasoning

  • Definition:
    • A normative approach aimed at establishing axioms or theories through observation and evidence.
    • Evaluates the truth of conclusions or axioms.
  • Example:
    • Every time Freya hears a collar jingle, the Devil appears. Conclusion: "If I hear the jingle, the Devil is coming."
    • Synthetic reasoning example: "I get tired if I don’t drink coffee. Coffee is addictive. Therefore, I am addicted to coffee."

Deductive vs. Inductive Reasoning: Summary

  • Deductive reasoning starts from general rules to specific cases, while inductive reasoning builds general conclusions from specific examples.

David Hume's Criticism of Induction

  • Hume questioned the validity of inductive reasoning, asserting that past experiences do not guarantee future occurrences.

Conditional Statements and Valid Rules of Inference

  • Form: If P, then Q.
    • Example: "If the Detroit Lions win the Super Bowl, then Michigan fans will celebrate."
  • To evaluate the truth:
    • If the Lions win (P), then fans celebrate (Q) - True.
    • If fans celebrate and the Lions lose, this contradicts the conditional relationship.

Valid Rules of Inference

  1. Modus Ponens (Affirming the Antecedent):

    • If P, then Q. If Tweety is a bird, then Tweety flies.
    • Valid if P is true.

  2. Modus Tollens (Denying the Consequent):

    • If Q is false, then P must also be false.
    • Example: If Bart is caught cheating, he writes on the chalkboard. If he is not writing, he wasn’t caught cheating.

Wason Selection Task

  • Objective: Identify which card(s) to flip to determine the truth of the statement: If P then Q (e.g., If a card has a vowel, then it has an even number).
  • Results Indicate: Confirmation bias often affects participants, leading them to select cards that confirm their expectations instead of testing the rules.

Matching Bias

  • People tend to choose values mentioned in the conditional statement, highlighting a bias in card selection.
  • Example Study Results:
    • Certain conditions consistently yield incorrect selections, emphasizing cognitive biases in reasoning.

Realism of the Rule and Schema Theory

  • Familiar or realistic contexts make reasoning tasks easier compared to abstract or symbolic contexts.
  • Example: Participants performed better on a task with practical everyday content compared to symbolic tasks.

Social Contract Theory

  • Proposed by Cosmides (1989), suggesting that human reasoning abilities evolved to navigate social contracts and environmental challenges.
  • Understanding societal rules might hinge more on perceived benefits and costs than on rational deduction.

Hostile Media Effects

  • Studies show observers' perceptions of media bias depend on their pre-existing beliefs (Hastorf & Cantril, 1954).
  • Research indicates individuals perceive media coverage of events through biased lenses that reinforce their views.

Confirmation Bias and Polarization

  • Example study by Lord, Ross, & Lepper (1979): Participants supported their views on capital punishment regardless of the evidence provided, demonstrating deep-seated biases.

Conclusion

  • Understanding reasoning involves navigating between normative theories (logic, validity) and descriptive theories (confirmation bias, schematic reasoning).
  • Both inductive and deductive reasoning play crucial roles in how conclusions are formed and justified in cognitive processes.