"What is your biggest weakness?" If you're pitching a potential investor or interviewing for a job and you get asked this dreaded question, what should you say? It all depends on what the person asking the question already knows about you.

That insight comes from Wharton professor, author, and TED speaker Adam Grant. In a recent piece about the perils of authenticity, Grant describes a fascinating study in which researchers from several universities across the globe studied international teachers applying for jobs in the U.S. and lawyers applying for jobs with the U.S. military--deliberately choosing two very different sorts of jobs and candidates. They looked at the candidates' agreement or disagreement with "self-verification" statements like this one: "It's important for an employer to see me as I see myself, even if it means bringing people to recognize my limitations." Then they compared those answers with the candidates' likelihood of actually landing the job.

Did self-verification help a candidate's chances, hurt them, or have no effect at all? The answer is yes to all three, depending on information the interviewer already had about the candidate, specifically his or her résumé. As Grant explains,

"The candidates who agreed with those statements were more likely to get job offers--but only if their résumés had been rated in the 90th percentile or higher. For the vast majority of lawyers and teachers, striving to be authentic didn't help their chances. And it actually hurt their chances if they were teachers in the 25th percentile or below or lawyers in the 50th percentile or below."

In other words, honestly admitting your own weaknesses will only help you if the person you're admitting them to already has good reason to trust you and respect your work.

Shoo-in or long shot?

So what does that mean if you're in a job interview or a pitch meeting and someone asks you this pernicious question? Your answer should partly depend on whether you believe, based on what the other person already knows, you're a shoo-in or a long shot. If you know you're a strong candidate already, then giving an honest answer may well help you land the job or the investment. To illustrate, the researchers describe the beginning of the movie The Devil Wears Prada, in which the protagonist, who's applying for a job as an assistant at a fashion magazine, admits that she's not glamorous and has little interest in fashion during her interview with the editor-in-chief. She lands the job, though, because she's very qualified in every other way, and her honesty makes her stand out from the crowd.

But what if landing this investment or this job is a stretch for you and you don't already have a proven track record that shows you deserve it? Then things get trickier. You probably won't win any points with an obvious humble-brag such as, "My biggest weakness is that I work too hard and care too much about getting results." But an honest answer about your shortcomings won't help your chances and could very well hurt them. Unfortunately, as Grant notes, this is even more true for nondominant groups, such as women and people of color, than it is for White men.

At the same time, hiding who you are has psychological costs that can also negatively affect your chances. "When entrepreneurs pitch their startups and job candidates pitch themselves, pretending to be someone they're not makes them nervous, interfering with the quality of their presentations," he writes. That's something to consider before giving a completely false answer.

A more useful approach might be to stop thinking only about yourself and focus for a moment on what the person asking the question wants and needs. "Some evidence suggests that being authentic hurts people who are low in concern for others," Grant writes. "They're liked less and receive poorer performance reviews."

So think about all you've learned through your background research on the company and your conversation thus far. Then give an honest answer, as much as you can, while being mindful of how your stated weakness might fit in with the culture and values of the organization and the person you're speaking with. Describe your weakness as one you're working to improve. Most important, make it clear that the person you're talking with can absolutely count on you to deliver what the organization needs. 

Authenticity isn't just about being yourself, Grant explains. It's also about having empathy for others. Keep that in mind, and you just might be able to answer "What is your greatest weakness?" in a way that's both true to yourself and will get you what you want.