'The Champ'It's easy to make someone cry. Just show them a key two-and-a-half-minute scene from what scientists have determined is the Saddest Movie Ever Made.

According to Smithsonian.com, scientific study has determined that the most reliable tearjerker of all time is 1979's 'The Champ,' in which washed-up boxer Jon Voight returns to the ring in order to earn enough to retain custody of his son, Ricky Schroder. Particularly, the climactic scene where -- spoiler alert! -- the little boy watches his battered dad die (end spoiler). It's a moment that makes Schroder and the hardened old men in the scene all bawl their eyes out, and it's all but guaranteed to do the same to you.

Those are the findings of James Gross and Robert Levenson (you can read their study in this PDF document), who spent years looking for the optimum film clip to make people cry so that they could serve as test subjects for other social scientists' experiments on how sadness affects people's behavior. Using film to induce tears was quicker, more efficient and more ethical than, say, telling people their families had been harmed or that they were suffering from some awful disease. After all, people willingly pay good money to see movies that make them weep, and they go home without being permanently traumatized.