There may be some truth to the old adage “All you need in life are a few good friends and a few good drinks.” Your circle of friends may be better judges of the personality traits you possess that are associated with longevity, at least, according to a study in a forthcoming issue in the journal Psychological Science.

The power of personality and its effect on how many birthdays you celebrate has been explored in scientific literature. Personality traits can predict important life outcomes like divorce, occupational attainment, and even mortality. Your outlooks in life can play an important role when it comes to your life span. For example, personality traits such as conscientiousness, are associated with longevity, according to "The Longevity Project," a book written by authors Howard S. Friedman and Leslie R. Martin who’ve encapsulated 80 years’ worth of research on personality traits and life span.

It’s important to remember many factors from genetics to lifestyle also play a vital role in determining life expectancy. However, with life expectancy at a record high in the U.S. for females 81.2 years and for males, it's 76.4 years, questions about whether certain personality types are more prone to premature death than others continue to become increasingly relevant. Researchers have established important connections between personality and health outcomes but have struggled with a way to accurately measure them — until now.

Joshua Jackson, lead author of the study at Washington University in St. Louis and his colleagues, decided rather than asking participants about their own personality traits, it would be better to combine the assessments of close friends. The research team used an existing data base called the Kelly/Connolly Longitudinal Study, launched in the 1930s, which studied the personalities and new marriages of 600 engaged men and women in their mid-20s. The participants’ personality self-ratings and the personality rankings by their five close friends were used for a comparative analysis. The researchers were able to track down either the participants themselves or their obituaries last year, according to The Huffington Post.

The findings revealed the participants’ friends were much better at identifying personality traits linked to longevity compared to the self-reporting by the participants. Men who were high in the personality domains of conscientiousness and openness to experience were found to live longer than those who lacked these traits. This was also found in men whose friends said they were conscientious and open to experience.

Conscientiousness and openness are two of the Big Five personality traits in psychology. The other three factors include extraversion, agreeableness, and neuroticism. These five dimensions are typically used to describe human personality.

Personality traits of agreeableness and emotional stability, especially when ranked by friends, were most highly linked to longevity for women. Since the data was collected in the 1930s, these traits were probably indicative of “a supportive and easy-going wife, the emotional leader of the family,” according to the press release. However, unlike men’s self-ratings, their own assessments of their personalities did not accurately predict their mortality.

In both cases, friends’ assessments of personality were able to accurately predict longevity. These results could have important clinical implications for doctors suggesting they should take their patients’ personalities into account when determining treatments. So perhaps we do get by with a little help from our friends.

Source: Jackson J et al. How long will you live? Ask your friends. Psychological Science. Forthcoming.