Working at the University of California, Berkeley, back in 1988, Robert Levenson and James Gross were researching the relationship between movie scenes and emotion. Specifically, they were searching for a scene that succeeded in eliciting only a single emotion at a time, Smithsonian Magazine reports. On the sadness front, the winner was as clear as it was surprising. 

After testing 78 carefully vetted sad movie scenes across almost 500 undergraduate volunteers, they discovered that the ending scene in Franco Zeffirelli's 1979 sports drama "The Champ" was distilled sadness, and evoked the emotion more often than any other scene. To put this in context, the second place went to the famous scene in "Bambi" where the titular character's mother dies.

Since the results of the research were published in 1995, "The Champ" has been used in a great many psychology experiments and features in over 300 papers, thanks to the scene's ability to cause sadness in test subjects in a powerful, yet comparatively ethical way. "It's wonderful for our purposes," Levenson said. "The theme of irrevocable loss, it's all compressed into that two or three minutes." 

Curiously enough, despite its off-the-charts emotional punch, critics don't consider "The Champ" a particularly great movie. It only has a 36 percent Tomatometer score on Rotten Tomatoes, so while scientists may be convinced of its importance, perhaps being a sad movie doesn't make it a good movie. Then again, its audience score is a respectable 82 percent, so maybe critics just don't like feeling sad.