RENEE MONTAGNE, HOST:
This is MORNING EDITION from NPR News. I'm Renee Montagne.
LINDA WERTHEIMER, HOST:
And I'm Linda Wertheimer. Today, in Your Health - why a life of purpose may be a longer life.
MONTAGNE: But first when a doctor tells a patient to undergo a test for a disease, the doctor may assume that the patient would want to know whether they have the disease. That's not always the case though. Often people prefer not to know, fearing bad news. Here's NPR's social science correspondent Shankar Vedantam but on some.
SHANKAR VEDANTAM, BYLINE: There's an old theory in economics about information, it makes common sense too. If I have some information about your finances or your health you should be willing to hear it. Maybe my information is useful, in which case you can act on it, maybe it's useless, in which case you can ignore it. If were a rational person says Josh Tasoff, an economist at Claremont Graduate University, here's one thing you should never do.
JOSH TASOFF: A person should never avoid information because information can never hurt a decision.
VEDANTAM: But of course people don't always behave rationally. We like information when the news is good and there other times we go, I'd rather not know. There's lots of new research that documents this behavior. Social scientists call it, information aversion. Tasoff and another researcher, Ananda Ganguly at Claremont McKenna College, recently decided to find out how information aversion, commonly called the ostrich effect, works in health. It's not rational to avoid accurate health information but what if the information is unpleasant. Here's the experiment they set up. They recruited a bunch of college students, they picked a subject.
TASOFF: Sexual transmitted diseases.
VEDANTAM: Tasoff says it's something lots of college students worry about. The students who volunteered were told they could get tested for the herpes simplex virus or HSV. It's a common disease that spreads via sex. It has two forms, one is unpleasant and the other is even worse. Ganguly says the college students were given information, graphic information that made it clear how bad herpes could be.
ANANDA GANGULY: There were pictures guaranteed to kind of make them really not want to have the disease.
VEDANTAM: Then once the students understood what herpes does, they were told a blood test could tell them if they had either form of the disease. Now in previous studies into information aversion it wasn't always clear why people declined information. So, Tasoff and Ganguly set out to eliminate the confusion by setting up the experiment in a certain way. First they wanted to make sure that students weren't declining the information because they didn't want to have their blood drawn. So, Ganguly came up with a way to fix that.
GANGULY: We were going to draw their blood anyway and discard the blood. If you can believe it we would draw 10 cc of their blood in front of them, have them pour it down the sink.
VEDANTAM: If the student elected to get the blood tested for herpes they would receive their results confidentially. So, being embarrassed was eliminated as a reason to decline the information. In fact Tasoff said the experiment was designed to eliminate every extraneous reason someone might decline to get information.
TASOFF: The idea is that all the costs associated with being tested are completely controlled for.
VEDANTAM: Finally, Tasoff and Ganguly added a step to the experiment to find out not just whether students wanted to avoid the information about herpes but how strongly they felt about not knowing. If students wanted to decline the test Ganguly told them they had to pay $10 and he asked them to think about it carefully.
GANGULY: You kind of have the sense that your blood is actually going to be wasted if you want to pay the money. So, you'd rather pay money, waste that blood than know what your test results were.
VEDANTAM: Did students declined to find out if they had disease? Yeah, quite a few. And Tasoff said there was a big difference in the number of students who avoided the test for the more unpleasant form of herpes. In fact three times as many students paid money not to find out they had genital herpes compared to herpes that causes cold sores.
TASOFF: For those who didn't want to know 85.7 percent, the most common explanation was because, quote, "it will cause me unnecessary stress or anxiety if I test positive."
VEDANTAM: Tasoff and Ganguly say their study and the growing body of evidence on information aversion, has a couple of important implications.
GANGULY: When we tell people, well you should get tested for disease X OR disease x, we tell them how bad it can be if they have those diseases it's something that we should look at as to whether we should scare people because scaring people more about the implications may scare them away from getting tested.
VEDANTAM: There's another take-home message Tasoff says.
TASOFF: Possibly, you know, an intervention that might address this is the routinization of tests. So, basically not draw their attention to it.
VEDANTAM: Both these ideas need more testing, but one thing seems clear, if you want people to pay attention to their health it doesn't make sense to stick our heads in the sand about the ostrich effect. Shankar Vedantam, NPR News.