Dissonance reduction can be achieved by changing cognition by changing actions, or selectively acquiring new information or opinions. To use Festinger's example of a smoker who has knowledge that smoking is bad for his health, the smoker may reduce dissonance by choosing to quit smoking, by changing his thoughts about the effects of smoking (e.g., smoking is not as bad for your health as others claim), or by acquiring knowledge pointing to the positive effects of smoking (e.g., smoking prevents weight gain).