If you dont want to be sick, just begin looking at sick people, a study has suggested.
Mark Schaller, a psychologist at the University of British Columbia and his colleagues hypothesized that seeing disease-connoting cues promotes a more aggressive immune response in people.
For testing the hypothesis, the scientist asked a group people to watch a 10-minute slide show of images of ill people, some suffering from chicken pox or sneezing or coughing.
A different group of people watched a slide show of images of people brandishing guns.
The participants rated the pictures of gun-touting thugs as more distressing than the pictures of sickly folks.
But blood samples taken from the participants before and after viewing the slide shows revealed that the bodily reactions were much different.
The researchers exposed the blood samples to a bacterial infection, and then measured the amount of an immune substance that white blood cells produce called interleukin-6, or IL-6. White blood cells normally secrete IL-6 when they detect microbial intruders.
The higher the level of IL-6, the stronger the reaction the white bloods cells are having against a possible infection.
People who saw the picture had white blood cells that increased their production of IL-6 by 6 percent.
The people who saw images of the infirmed had white blood cells that increased their production of IL-6 by 23 percent.
"It seems that there is something specific about seeing people who look diseased that triggers the immune system to kick it into a higher gear," said Mark Schaller.
The researchers have no idea as to why this happens, but they speculate it is a survival mechanism, enlisting mind or matter.
"If you see a bunch of people around you who look sick, that's a pretty good indicator that you're in imminent danger of infection. Which means that this is one of those times when it'd be wise to allocate more of those precious bodily resources to mount an especially vigorous immunological defense," said Schaller.
The study has been published in Psychology Today.