They were present in the mind and reacted immediately. That is why they will probably be among the first to know more about the gigantic stress experiment that Corona means for society. When the lockdown came, the team led by the Heidelberg medical psychologist Beate Ditzen sent lots of saliva sample sets to the households of 250 volunteers, including all life forms, twice six tests per person. Because the hormone level in saliva can be used to measure stress factors. In addition, a series of text messages was sent to each participant on the cell phone with the questions: How stressful do you find the lockdown? How useful? How stressed do you feel? Do you have physical contact with others?