With a subset of conditions that caused participants to question the credibility of the source in the movie, participants later reported a slight increase of persuasion (much to the researchers’ surprise). After examining the results, they initially hypothesized that forgetting of the discounting cue (in this case, the non-credible source) was causing the effect. Over time, however, the effect of the messages presented by credible sources decayed, whereas the effect of the messages presented by non-credible sources either remained the same or increased slightly. Despite evidence for the sleeper effect from this series of studies, the recall measures indicated that recipients could still remember the non-credible sources of the messages at the time of the delayed follow-up.