What did Festinger and Carlsmith's experiment demonstrate about the relationship between behavior and attitude?

Behavior can influence the formation of attitude.

There are instances where behavior can influence attitudes. Festinger and Carlsmith conducted an experiment where students were paid only one dollar to convince others that a particular experiment was interesting. Interestingly, the students ended up developing a positive attitude towards the experiment based on their behavior, reasoning that they wouldn't have lied for such a small amount of money if the experiment wasn't genuinely interesting.