Dual processing - Wason

Question 1

Aim

Answer 1

To investigate how people reason about conditional statements and whether they rely on intuitive (System 1) or analytical (System 2) thinking.

Question 2

Participants

Answer 2

Adult volunteers, often university students, asked to complete a logical reasoning task.

Question 3

Method

Answer 3

A laboratory experiment using a card selection logic puzzle.

Question 4

Procedure

Answer 4

• Participants were shown four cards, each with a letter on one side and a number on the other. Example cards: A, K, 4, 7
• They were given a rule:
• “If a card has a vowel on one side, then it has an even number on the other.”
• They had to choose which cards to turn over to test the rule.
• Correct logical answer: A and 7 (You must check the vowel card, and you must check the odd number card to see if it violates the rule.)
• Most participants chose A and 4, which is incorrect.

Question 5

Results

Answer 5

• Most people failed the task.
• They relied on System 1 thinking (fast, intuitive, pattern matching).
• They did not engage System 2 logical reasoning.
• Their choices showed a confirmation bias — they tried to confirm the rule rather than test it logically.

Question 6

Conclusion

Answer 6

• The study supports the Dual Processing Model:
  o System 1 → quick, intuitive, error prone
  o System 2 → slow, deliberate, logical
• Participants defaulted to System 1 even when System 2 was needed.
• This demonstrates how intuitive thinking can lead to faulty reasoning.

Question 7

Strengths - evidence

Answer 7

• Clear evidence for System 1 dominance Participants consistently chose the intuitive but incorrect cards, showing how System 1 (fast, automatic thinking) overrides logical reasoning. This directly supports the Dual Processing Model.
• Demonstrates the need for System 2 The correct solution requires System 2 (slow, analytical thinking), but most participants failed to engage it. This contrast makes the study a strong demonstration of the two system framework.

Question 8

Strengths - replicable, theoretical contribution

Answer 8

• Highly replicable Many replications show the same pattern of errors, strengthening the reliability of the claim that humans default to System 1 in reasoning tasks.

Question 9

Limitations - ecological validity

Answer 9

• Low ecological validity The card task is abstract and artificial, so it may not reflect how System 1 and System 2 operate in real life decision making. This limits how far we can generalise the model.

Question 10

Limitations - sampling bias

Answer 10

• Sampling bias Participants were often university students, who may have more experience with logic tasks. This makes it harder to generalise the findings to the wider population.

Question 11

Limitation - oversimplification

Answer 11

• Task may oversimplify thinking The Dual Processing Model assumes a clear split between System 1 and System 2, but real thinking is often more blended. The Wason task may exaggerate this separation.

Question 12

Limitations - demand characteristics

Answer 12

• Cultural and educational differences Performance improves in groups with more formal logic training, suggesting that the dominance of System 1 may not be universal.