Wouldn’t it be great to gain instant insight into how people feel about themselves? Knowing whether someone is an optimist, has healthy self-esteem, or possesses certain characteristics could be useful on both the personal and the professional levels.

Gaining this information on a first date could help you decide whether someone has long-term potential. After all, who wants to spend their life with someone who is likely to need constant reassurance that they’re doing a good job?

If you’re a hiring manager, knowing how positive or negative someone is should be a key factor in your decision-making process. Studies show negative people can cost a company $14,000 a year.

The good news is, there’s one question that can help you uncover how someone feels about themselves and how positive or negative that individual is.

The way individuals describe others reveals their true selves.

A 2010 study led by a psychology professor at Wake Forest University concluded that your perceptions about others actually reveal a lot about your personality and how you feel about yourself.

In a series of experiments, college students were asked to rate the positive and negative characteristics of three people–such as an acquaintance on campus. Based on the answer to that question, researchers were able to accurately predict the rater’s well-being, mental health, and social attitudes.

Just as the researchers predicted, individuals who described others in positive terms were positive people. In particular, people who described others as enthusiastic, happy, kind-hearted, courteous, emotionally stable, and capable were most likely to possess those characteristics themselves.

In contrast, negative perceptions of others were linked to higher levels of antisocial behavior and narcissism. A tendency to see people in a negative light also revealed potential mental health issues, such as depression or personality disorders.

The authors concluded that how positively you see others reveals how satisfied you are with your life and how much others are likely to like you.

How hiring managers can use this information.

Asking people about their greatest strengths or their greatest weaknesses isn’t likely to give you useful information about who someone actually is. People are more likely to share what they wish were true about themselves than how they actually are.

Instead, ask them to describe three of their current co-workers or couple of former supervisors. You could also take out a couple of stock photos of people and ask, “What sort of personality or characteristics do you think this person has?”

Listen carefully and you’ll discover a lot about that person’s self-esteem, characteristics, and psychological well-being as they actually describe themselves.

It could be the simplest yet most effective way to determine if you’re hiring someone who is going to be a good fit with your company.

Originally published at www.inc.com