A new Applied Psychology study asks why brain teaser questions are often used in employment interviews despite their known lack of validity and reliability. The authors provide evidence that these questions may be used because they give the interviewers power and speak to their ‘dark personality traits.’

The study notes that companies such as Xerox, Microsoft, and Zappos are purported to ask applicants such questions as “Why is a tennis ball fuzzy?” “Why are manhole covers round?” and “How many cows are in Canada?”

These oddball questions are not limited to employers in the United States, as several European employers have adopted the practice as well.

For the study, 736 participants were provided with various interview questions and asked if they would consider using them when hiring someone. They then completed questionnaires that assessed their personality traits.

Participants who would consider using brainteaser interview questions when hiring someone were more narcissistic, more sadistic, less socially competent, and believed more strongly in the power of intuition in the hiring process.

“Use of brainteasers in the hiring process provides little information about the suitability of the job applicant but considerable information about the callousness of the interviewer,” said co-author Dr. Scott Highhouse, of Bowling Green State University, in Ohio.