Do you have an employee who doesn’t follow through on her promises? What about a coworker who exaggerates his accomplishments or tinkers with the numbers? Chances are these folks duped someone during the hiring process into overestimating their potential.

In organizations, nowhere is judging character more important than in evaluating talent. When screening prospective executives and employees, company leaders constantly make predictions about whether these candidates will act in good faith and measure up to the requirements of their roles, or if they have oversold their talents and will have a negative impact on colleagues and the bottom line. So who excels at distinguishing the givers from the takers? Is it the skeptical leaders who harbor suspicions about others, or the trusting leaders who assume the best?

Lie detection is a notoriously difficult skill to master. In fact, even most so-called lie detection experts — experienced detectives, psychiatrists, job interviewers, judges, polygraph administrators, intelligence agents and auditors — hardly do better than chance. In a massive analysis of studies with more than 24,000 people, psychologists Charles Bond Jr. and Bella DePaulo found that even the experts are right less than 55 percent of the time.

Still, some people are better judges of character than others. So when we need to count on people to assess honesty, we tend to turn to the skeptics among us, expecting that they’ll be thorough and discerning.

Consider a clever study by psychologists Nancy Carter and Mark Weber, who presented business professionals with a scenario about an organization struggling with dishonesty in its hiring interviews. They had the chance to choose one of two highly competent senior managers to be the company’s job interviewer. The major difference between the two managers wasn’t experience or skill, it was a matter of personality: One manager was skeptical and suspicious, whereas the other manager had a habit of trusting others. Eighty-five percent chose the skeptical manager to make the hiring decisions, expecting the trusting manager to be naïve and easily duped.

But are we right that skeptics are better lie detectors? To find out, Carter and Weber created videotapes of eight business students interviewing for a job. Half of the interviewees told the truth throughout the interview, while the other half was instructed to tell three significant lies apiece.

Carter and Weber recruited a group of people to watch the videos. Several days beforehand, they had completed a survey about whether they were generally skeptical or trusting of others. After watching the videos, the participants placed their bets about which candidates lied and which told the truth, and then made a choice about which ones they would hire.

The results were surprising. The more trusting evaluators better identified the liars among the group than the skeptics did, and were also less likely to hire those liars.

Contrary to conventional wisdom, it’s the skeptics who are easiest to fool. Why would this be? One possibility, according to Carter and Weber, is that lie-detection skills cause people to become more trusting. If you’re good at spotting lies, you need to worry less about being deceived by others, because you can often catch them in the act.

The other possibility is that by trusting others, we sharpen our skills in reading people. Skeptics assume that most people are hiding or misrepresenting something. This makes them interpersonally risk-averse, whereas people who habitually trust others get to see a wider range of actions — from honesty to deception and generosity to selfishness. Over time, this creates more opportunities to learn about the signals that distinguish liars from truth tellers. It’s this latter explanation, that trust improves our lie detection skills, that I find more plausible. Children develop beliefs about the integrity and benevolence of others early in life, often years before they can master the art of spotting con artists.

So what signals do trusters use to spot lies? One of the study’s findings is that they pay more attention to vocal cues than skeptics do. This lines up beautifully with a breakthrough review led by the psychologist Alder Vrij. His team examined several decades of research and concluded that most of us rely heavily on nonverbal cues, such as nervousness or confidence, even though they can be misleading.

To effectively spot lies, Vrij and colleagues recommend renewed attention to verbal cues-inconsistencies in stories and incorrect responses to questions for which you already know the answer. These cues are most likely to emerge when the dialogue is mentally challenging (as lies are harder to remember than the truth) and when questions are unexpected (as candidates won’t have a scripted answer).

Because every conversation and candidate is different, the red flags that matter will ultimately vary in each interaction. This means that we need leaders who demonstrate skill in recognizing dishonesty. Instead of delegating these judgments to skeptics, it could be wiser to hand over the hiring interviews to those in your organization who tend to see the best in others. It’s the Samaritans who can smoke out the charlatans.

Of course, faith in others can go too far. It’s important to sprinkle a few ounces of skepticism into each pound of trust. Ultimately, while the best leaders don’t trust all of the people all of the time, the keenest judges of character may be the leaders who trust most of the people most of the time.

Adam Grant is a Wharton professor and the author of “Give and Take: A Revolutionary Approach to Success,” out April 9, 2013.

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