Which is true of the sleeper effect? People high in need for cognition initially distrust messages coming from noncredible sources, but will eventually forget the source of the message. People are unable to discern the credibility of sources, and will eventually forget the source of the message. People initially distrust messages coming from noncredible sources, but will eventually forget the source of the message. People in a positive mood are unable to discern the credibility of sources, and will eventually forget the source of the message.