Your Friends Sort of Know When You’ll Die

Pacific Standard:

Your friends know you better than you know yourself. They even know how long you’ve got to live. Well, roughly speaking they do.

It’s not that they’ve got extrasensory perception, time machines, or membership in the secret conspiracy that surrounds you. It’s just that psychological traits like conscientiousness and emotional stability are decent predictors of longevity, and your friends’ beliefs about your traits are, when averaged, more reliable than your own.

Researchers know that personality traits affect health—conscientiousness, for example, turns out to be a pretty good predictor for risk of death. But the studies linking personality, health, and mortality are limited because they rely on participants’ assessments of their own personalities. Apart from the bias that might introduce, it’s also privy to external factors which could sway the participant—say, the weather that day. Fixing this validity problem would take a study in which researchers asked someone else—preferably friends, who see one another in a variety of situations—about individuals’ personalities.

That’s just what Joshua Jackson and colleagues did with the long-running Kelly Longitudinal Study, which began as an assessment of 300 young married couples in mid-1930s Connecticut. As part of the study, the late psychologist E. Lowell Kelly asked three to eight of each couples’ friends to answer a series of questions Kelly had constructed to probe personality.

Read the whole story: Pacific Standard