Step 1: Understanding the Concept:
The experiment conducted by Leon Festinger and James Carlsmith in 1959 is one of the most classic studies in social psychology. It aimed to test the theory of cognitive dissonance. Cognitive dissonance is the mental discomfort experienced by a person who holds two or more contradictory beliefs, ideas, or values, or is confronted by new information that conflicts with existing beliefs, ideas, or values.
Step 2: Detailed Explanation:
In the experiment, participants were asked to perform a very dull and repetitive task. Afterwards, they were paid either \$1 or \$20 to tell the next participant that the task was enjoyable and interesting. The key finding was that those who were paid only \$1 (insufficient justification for lying) later rated the boring task as more enjoyable than those who were paid \$20. The \$1 group experienced high dissonance (My behavior of lying contradicts my belief that the task was boring), and since the external justification (\$1) was low, they reduced the dissonance by changing their attitude to believe the task was actually somewhat fun.
Step 3: Final Answer:
The famous Festinger and Carlsmith experiment was designed to demonstrate Cognitive dissonance.