Narrator: This is Science Today. Various studies have found that family members and doctors are often unaware of patient preferences when it comes to do-not-resuscitate orders or other life-and-death decisions. Peter Ditto, a professor of psychology and social behavior at the University of California, Irvine, found this to be the case in a study of living wills, or advance directives.
Ditto: What I'm really interested in is getting sort of the psychology of advance directives. How is it that people can try to decide in advance what sort of medical treatments they would want if they're in a very serious medical condition - a state very different from the one they're in now.
Narrator: Ditto found that for the most part, advance directives did not significantly help people accurately predict patient preferences.
Ditto: The point that the research makes is that if you believe that a simple statement like that is going to communicate your wishes with somebody else, that's not a good assumption. That it's going to at least take a more elaborate process. It's an ongoing process of discussion sort of examining the reasons for people's wishes, the values that underlie their wishes.
Science Today, I'm Larissa Branin.