If you’ve ever been a strong candidate for a C-suite position, chances are you’ve undergone a personality and behavioral assessment. It’s that online questionnaire with hundreds of questions about your preferences, beliefs and feelings, many of them difficult to answer, some repeated multiple times using different wording. You get a sense that they’re trying to trick you.

That’s because “they” are. It’s a conspiracy of sorts, involving some combination of prospective employer, recruiting firm, and the developer of the test.

Of course, companies have good reason to be interested in how its next CEO or CFO might behave in particular circumstances. If you want a senior executive position, it’s something you have to get past, even if it amounts to a figurative pole vault.

Then again, candidates for such positions are smart. Is it not possible for them to perceive what the “correct” answers are, the ones that will give them the best chance to land the job?

“If the question is ‘is it possible,’ the answer has to be yes,” says Richard Metheny, who heads the Leadership Solutions practice at recruiter Witt/Kieffer and has been assessing executives for more than 20 years. “But the possibility is incredibly small.”

The prevalence of companies requiring executive candidates to complete an assessment has boomed over the past few years, according to Metheny. Since the firm developed a new set of assessments three years ago, it’s assessed about 700 executives, he says. In only four or five of those cases did Metheny spot what those in the assessment field call “positive fakers” or “impression managers.”

“Even if you are aware of what traits you have that might not play well in this hiring situation, it’s difficult to do because of the way the assessments are constructed,” he says. “When you’re answering 400 questions and see the same one asked three times in three different ways, it starts to get complex.”

There’s a huge amount of research that validates the efficacy of behavioral assessments, Metheny says. For example, a large group of people were given an assessment and shown the results. Later they were told they had another chance to take the test, and that the results would used for determining promotions. “If there was ever a time to game it, that was it,” Metheny says. Yet the results were almost identical to the first assessment.

He acknowledges that experience, skills, and knowledge are the most important factors in selecting a top executive. But if there are multiple candidates that are about even in those areas, “then the assessments can be very helpful in making a final decision.”

A key purpose of the assessments is to identify “derailing” behaviors — those that appear infrequently but regularly that could impede or derail an executive’s success. But the presence of such traits shouldn’t necessarily disqualify a candidate, Metheny advises.

“Most people have potentially derailing behaviors, at least to some degree. But hiring someone with your eyes wide open is a lot different than having to call me nine months later asking what’s going on with this person you thought was going to be fantastic.”

Companies frequently want to know whether behavioral assessments can predict whether an executive is likely to stick around for several years. “I can’t answer that,” Metheny says. “What I can say is that there can be indications that someone has a strong interest in upward mobility. But if that person also has strong values, and the company creates an environment in which the person can actualize those values, it will be harder for him or her to leave.”