Your Co-worker or Fellow Plane Passenger May Be Sick and Lying to You

2 min read

Jan. 30, 2024 – A new study suggests that getting sick brings on more than sniffles or a fever. For most people, it brings out the sneaky in them. 

An impressive 75% of people admitted they have concealed an infectious illness, according to a new study led by University of Michigan researchers. Among people in the study who were health care workers, more than 6 in 10 said they didn’t report their illness, actively tried to cover it up, or planned to keep a future illness secret.

The findings come from an analysis of pooled data from previous studies that examined people’s behaviors or intentions regarding past, current, and future illnesses. The new results were published this month in the journal Psychological Science and combined data from about 4,100 people. The people in the studies were university students in the U.S., health care workers, or responded to online survey invitations.

Reported behaviors included concealing an illness even when getting on airplanes or going on dates, according to a summary of the study from the Association for Psychological Science.

“Disease concealment appears to be a widely prevalent behavior by which concealers trade off risks to others in favor of their own social goals, creating potentially important public health consequences,” said lead author Wilson Merrell, PhD, a post-doctoral researcher at Aarhus University in Denmark, in a statement. (Merrell was a doctoral student of psychology at the University of Michigan while working on the research.)

People’s intentions and actions regarding infectious illness vary greatly, the researchers found. When asked to imagine having a harmful or mild illness, people more often said they would be less likely to conceal a harmful illness. But people who were actually sick frequently hid their illness, regardless of illness harm. 

“Sick people and healthy people evaluate the consequences of concealment in different ways, with sick people being relatively insensitive to how spreadable and severe their illness may be for others,” Merrell said.

Some people reported falsifying their responses on mandatory illness screening tools such as those used by employers or universities during the pandemic. Many said they covered up an illness because it would conflict with social plans.

Among a group of college students whose university used a screening tool to ask if they were sick before allowing entry to campus buildings, 41% said they attempted to conceal an illness.

“This suggests that solutions to the problem of disease concealment may need to rely on more than just individual goodwill,” Merrell said.