Narrator: This is Science Today. Over the last decade, there's been a major push in this country to advocate the use of advance directives - or living wills - but according to Peter Ditto, a psychology and social behavior professor at the University of California, Irvine, the policy has gotten ahead of the science.
Ditto: Every major medical organization suggests that people should complete these, but nobody had really looked to see whether they accomplished the things that they were supposed to accomplish. Can people really make decisions for a future self that's very different from where they are now? Can other people understand people's wishes?
Narrator: According to Ditto's findings, the answer is - not really.
Ditto: Now that doesn't mean that a longer-term discussion or some other sort of intervention might not do better, but it means that the simplest version of this isn't working the way that advance directives aren't accomplishing what they're supposed to accomplish.
Narrator: For Science Today, I'm Larissa Branin.