In my multi-decade career at Cornell University, I've had the opportunity to mentor many exceptional students--many who went on to be CFOs, CEOs, and entrepreneurs. A few weeks ago, one of my students was being interviewed for a position. He had a great résumé, and did wonderfully well on the various interview rounds, but stumbled on the "brainteaser." This student was one of the most exceptional I've mentored in recent years. I was astonished that a brainteaser had so much weight in the hiring decision. What about record? The recommendations? The experience? Are brainteasers that important? In this day and age, I think brainteasers could easily shut out your best candidate.

Brainteasers can be administered by paper and pencil, or they can be delivered online. Essentially, a brainteaser scheme will take the candidate through a battery of problem-solving scenarios, and the results are used as a proxy for how well the candidate may fare in a particular job. The brainteaser, as an interview tool, is flawed for the following reasons:

1. Brainteasers create stress and harm interview performance. A recent study shows that stress is negatively correlated with interview performance: The more stressed the candidate, the worse he or she will perform during the job interview. The interview process is overlaid with stress, and candidates are painfully aware that a poor interview performance can have implications for the trajectory of their career. Brainteasers only add more stress to the equation. As such, they can increase the likelihood of poor interview performance.

2. Brainteasers are difficult to prepare for. Interview prep for the serious candidate is intensive. Depending on the situation, it can take hours for candidates to research the prospective employer and practice responses. While the curve-ball question can be used to see how candidates think on their feet, the brainteaser is a whole new ball game. There are thousands of brainteasers that can be culled from the fields of algebra, philosophy, and logic. Because of the wide variation of brainteaser questions, the candidate can bone up on the current favorites, but he or she will never be totally prepared for the brainteaser segment of an interview. The fact that brainteasers can be found during a quick Google search negates any true assessment of one's creative or psychological fit for a particular job.

3. Scoring of brainteasers is subjective. Even though the array of brainteasers is nearly endless, they fall into one of two camps: those that require a precise answer, and one where a ballpark guess is appropriate. The skills being tested are slightly different. The test giver needs to consider if mathematical precision is important, or if the ability to make a fair estimate is more valuable. People have different strategies when coming up with an estimate, and while some may not be "textbook" approved, they still work. If someone has an unconventional method for reaching the answer, how is that rated? Bias and subjectivity come into play. Often, interviewers rate a candidate's solution on the basis of how attractive his or her particular problem-solving approach was to them, rather than on how creative the process coming up with the answer was.

4. Brainteasers are not predictive of candidate intelligence or potential job performance. Brainteasers are not substitute experience, education, IQ, or any other criteria the employer may deem of importance. In fact, brainteaser performance predicts neither intelligence nor job performance. Studies show that there is a low correlation between a candidate's ability to solve brainteasers and intelligence level. Leaders at Google, a company notorious for having extensively used brainteasers in the past, have questioned their ability to predict anything. In an interview, Laszlo Bock, then senior vice president of people operations at Google, notes, "How many golf balls can you fit into an airplane? How many gas stations in Manhattan? A complete waste of time. They [brainteasers] don't predict anything. They serve primarily to make the interviewer feel smart."

In candor, I am one Ivy League professor who could not do a brainteaser if my life depended on it. But I have survived in life. The fact is that some people are good at brainteasers and others are not. Brainteasers assure nothing. Looking into the future of work, hiring managers should be looking for pragmatic commonsense, an ability to work with teams, entrepreneurship, a touch of leadership, and core professional competence. The ability to do brainteasers guarantees none of this.