How Many Days Would It Take to Carve This Post in Stone With a Toothpick?

Google is famous for its brain-teasing job interview questions. How would you survive as a 5-millimeter-tall person in a blender? How would you move Mt. Rainier? Or, if not exactly that, at least that sort of thing.

The idea is to see how the interviewee thinks. Except Google has found that it’s pointless. “On the hiring side, we found that brainteasers are a complete waste of time,” revealed Laszlo Bock, senior vice president of people operations at Google, in a recent interview in the New York Times. Bock added, “They don’t predict anything. They serve primarily to make the interviewer feel smart.”

That’s not the only thing Bock has found. Google has been running studies on what has worked in hiring and what hasn’t, and it has found that how interviewers score a candidate and how the person performs have almost no correlation. “It’s a complete random mess,” Bock said. Only “structured behavioral interviews, where you have a consistent rubric for how you assess people,” seem to have any useful effect.

Peter Drucker would have found all of this interesting—even as it confirmed many of his own findings. On the one hand, as we’ve discussed, he might have liked brainteasers in theory—as a form of talent scouting for bright people with less education, for instance.

But he would have been unsurprised to find they generally don’t work. Drucker felt that when it comes to questions of human potential, most of us are fumbling in the dark.

“Not only are few of us reliable judges of a man; nothing, also, may change as much as potential,” Drucker wrote in The Practice of Management. “The world is full of men whose youthful promise of excellence has turned into middle-aged mediocrity. It is full of men who started out as pedestrian plodders only to blossom out into star performers in their 40s. To try to appraise a man’s long-range potential is a worse gamble than to try to break the bank at Monte Carlo; and the more ‘scientific’ the system, the greater the gamble.”

As for the brainpower brainteasers might reveal, Drucker felt that “brilliance” was overrated. Honesty, in his view, mattered more. Great bosses, he noted in Management: Tasks, Responsibilities, Practices, “never rate intellectual brilliance above integrity in others.”

Do you think brainteasers have a useful role to play in certain job interviews? Why or why not?