Natalie Portman wept in 2011. Halle Berry sobbed in 2002. Tom Hanks choked back tears in 1994.
Crying can be as much a part of winning an Oscar award as thanking loved ones and the Academy. In fact, happy tears are so prevalent that bookmakers like Ireland's Paddy Power have been known to take bets on whether performers will break down and cry when handed the coveted statuette.
Sure, pain and suffering often make us blubber. But why do happiness and victory cue the water works?
As neuroscientist Robert Provine, author of Curious Behavior: Yawning, Laughing, Hiccupping and Beyond, explains, it is important to distinguish between two kinds of crying – vocal crying, typical of a newborn demanding to be fed, which is an ancient behaviour shared with other animals, and emotional crying, the tears of happiness or sadness, which is a recent evolutionary development exclusive to humans.
"Only humans shed emotional tears," Provine says.
Emotional tearing acts as a visual signal that communicates intense feelings and amplifies people's expressions, he says. It is, however, an imprecise signal, he says. If a weeping award winner were to stop smiling, for instance, one could easily mistake his or her tears for sorrow.
"It's a crude instrument and so to make sense of these emotional tears, you really need to know something about context," he says. "You need to know what else is going on."
Though it's a form of communication, crying is largely involuntary, Provine adds. "You don't decide to cry," he says, noting that performers often rely on method acting, which involves putting themselves in a scenario that makes them cry. "It takes a special kind of end-run around our nervous system."
With a lack of research on the subject, little is known about the hows and whys of joyful crying, says behavioural neurologist Michael Trimble, author of the recently released book, Why Humans Like to Cry: Tragedy, Evolution and the Brain.
However, previous studies have shown that the chemical makeup of emotional tears are different from tears caused by an irritant, like chopping an onion, Trimble notes in his book. Emotional tears are found to have a higher protein content, and have different levels of peptides, like adrenocorticotropin, prolactin and enkephalin.
Contrary to popular wisdom that crying offers a sense of catharsis, or a feeling of calm and relief, sobbing in grief actually increases activity in the autonomic nervous system, Trimble said in an interview. Yet he notes that people often report feeling better, at least psychologically, after a good cry. He says it's unclear whether the same effects take place with happy crying.
When it comes to tears of laughter, however, he says the act of laughing tenses up the facial muscles, putting pressure on the muscles around the eyes, which increases tearing. In addition, laughter triggers a reflex signal to the brain that causes the lachrymal glands around the eyes to produce tears.
One thing that is apparent about joyful tears, Trimble suggests, is that they tend to be short-lived compared to tragic tears. So while Oscar winners may choke up during their speeches, they can enjoy the rest of the evening relatively dry-eyed.
Not so for the losers, Trimble says. "Those who cry – who've lost the competition but who expected to win – that agony, those tears of loss, go on longer."