Your best friends could be the best judges of how long you're going to live.
New research suggests friends are best at recognizing how your behavior in one's early 20s will influence their lifespan, Washington University in St. Louis reported.
"Our study shows that people are able to observe and rate a friend's personality accurately enough to predict early mortality decades down the road," said Joshua Jackson, assistant professor of psychology in Arts & Sciences. "It suggests that people are able to see important characteristics related to health even when their friends were, for the most part, healthy and many years from death."
Personality traits such as depression and anger have been largely linked to early death. Conscientious men are more likely to take care of their bodies and avoid risks such as not wearing a seatbelt, and women who are emotionally stable are less likely to battle anger, anxiety and depression.
To make their findings the researchers looked to a study starting back in the 1930s that started following a group of people in their 20s. The study included data on participant personality traits that were both self-reported and as their friends perceived them. The researchers were able to find documentation on the deaths of most of the study's participants. The team determined peer personality assessments were more accurate in predicting mortality than self-assessments.
"There are two potential reasons for the superiority of peer ratings over self ratings," Jackson said. "First, friends may see something that you miss; they may have some insight that you do not. Second, because people have multiple friends, we are able to average the idiosyncrasies of any one friend to obtain a more reliable assessment of personality. With self reports, people may be biased or miss certain aspects of themselves and we are not able to counteract that because there is only one you, only one self-report."
The findings were reported in a recent edition of the journal Psychological Science.