Mina Cikara of the Massachusetts Institute of Technology and Susan Fiske of Princeton University measured the electrical activity of cheek muscles with an electromyogram, which captures the electrical activity of facial movements when an individual smiles.
Participants were shown photographs of individuals associated with different stereotypes: the elderly (pity), students or Americans (pride), drug addicts (disgust) and rich professionals (envy).
These images were then paired with everyday events such as: "Won five dollars" (positive) or "Got soaked by a taxi" (negative) or "Went to the bathroom" (neutral). Participants were asked how this would make them feel, and their facial movements were recorded.
"Because people don't like to report envy of Schadenfreude, this was the best method for gathering such responses. And, in this experiment, we were able to viscerally capture malicious glee," Fiske said. "We found that people did smile more in response to negative than positive events, but only for groups they envied."
In a second study, participants viewed the same photographs and events as the first study and were asked to rate how they felt on a scale of 1-9.
Similar results emerged: Participants felt the worst about positive events and the best about negative events in regards to the rich professionals, the study said.
"A lack of empathy is not always pathological. It's a human response, and not everyone experiences this, but a significant portion does," Cikara said. "If you think about the way workplaces and organizations are set up, for example, it raises an interesting question: Is competition the best way to get your employees to produce? It's possible, in some circumstances, that competition is good. In other ways, people might be preoccupied with bringing other people down, and that's not what an organization wants."
The findings were reported in the Annals of the New York Academy of Sciences.