Stress, like yawning, can be contagious, researchers in Germany have found. They said that simply observing someone in a stressful situation often causes a person's body to release the stress hormone cortisol, a phenomenon they term "empathetic stress."
The team of researchers, led by Tania Singer, director of the Department of Social Neuroscience at the Leipzig-based Max Planck Institute for Human Cognitive and Brain Sciences (MPI CBS), and Clemens Kirschbaum, a professor of biopsychology at the Dresden University of Technology, subjected 151 people to stressors such as complex mental arithmetic and job interviews.
The test persons were variously paired with 211 observers - either a loved one or a stranger of the opposite sex - who watched them in "real life" through a one-way mirror or via a live video transmission. Overall, 26 percent of the observers displayed "significant cortisol increases," the researchers said.
The figure was 40 percent when the test person was a loved one compared with 10 percent for strangers, and 30 percent during a real-life observation compared with 24 percent for a virtual one.
"This means even television programmes that confront me with other people's suffering can transmit their stress to me," said Veronika Engert, a research assistant at MPI CBS. The study was published in the journal Psychoneuro endocrinology.