Final answer:
Leon Festinger originated the term cognitive dissonance to describe the mental discomfort when there's a conflict between a person's beliefs and behaviors, such as a smoker who believes smoking is bad but continues the habit nonetheless.
Step-by-step explanation:
Leon Festinger is credited with originating the term cognitive dissonance to refer to the psychological discomfort and mental tension experienced when a person's behavior does not match his or her attitudes, or when two ideas are not congruent. This concept is a fundamental theory in social psychology that suggests our beliefs are affected when we experience a threat to our self-esteem or positive self-image. When beliefs and behaviors conflict, we experience dissonance and are motivated to reduce this discomfort by changing our cognitions, attitudes, or behaviors to become more harmonious and consistent. An example of cognitive dissonance is a smoker who continues to smoke despite believing it is bad for their health, thus experiencing conflict between their belief and their behavior.