A teacher used the following statement to change the behaviour of a student who was a smoker: 'Smoking is healthy for the nation.' This is an example of

Cognitive dissonance, named by Leon Festinger, is the mental discomfort of holding two clashing beliefs, and the absurd claim jars with the smoker's own knowledge to push a behaviour change.

Conceptual conflict is a clash between ideas within a subject, not the personal tension Festinger described.

Meaningful learning of David Ausubel links new material to existing knowledge, unrelated to inducing discomfort.

Challenge is merely a difficult task set before a learner, not an inner contradiction.

Festinger set out cognitive dissonance in 1957 in his work A Theory of Cognitive Dissonance.

People reduce dissonance by changing a belief, changing the behaviour, or adding new justifying thoughts.