I came across a question on the Q&A site Quora a few years ago while browsing about how to assess candidates during interviews. We're limited in the information we can really know about a person in the context of most interview settings. People are usually not completely comfortable, they're not being fully themselves, and they're hyper on their guard to hide any character flaws they might have. Basically the observer effect is a massive barrier to actual insight.

So, the question is, if you could peek into any aspect of a person's personal life before making a hiring decision, hypothetically, what would it be?

My answer: I'd want to observe them driving in traffic. Not just driving on the road, but driving where there are lots of other drivers around, in a few different settings, and see how they conduct themselves relative to the conditions of the road and the behavior of the other drivers.

Often, when I'm on the highway in the fast lane, traffic is slower than I'd like in all of the lanes, and in my lane, and there's a long procession of cars ahead of me going this speed as far as the eye can see. In this case, if there's no way around, I just hang back with reasonable following distance, and put on an audiobook or some music.

You've been there before: as you patiently cruise along, someone comes up behind you and starts riding ride on your back bumper, ostensibly annoyed that you're going so slowly. After a little while, if they haven't pulled back and are right on my ass, I'll move over to the right and let them pass me. Their reaction seems to say "Finally!" and they floor it right up to to back bumper of the next car in front of them...at which point they're right back where they were before I moved, but a few car lengths up. I've seen people do this at length, with each car ahead of them getting out of their way, and they manage to gain a couple of hundred feet of advancement in the space of 20 minutes.

This is, I think, the level at which most people in the world operate. If you look ahead, beyond what is right in front of you, with a little bit of common sense, you'd understand that even if the car ahead of you were to move, they're still a long processional of blockers that you have no way to get around. But this kind of person is not looking at all those other cars and don't understand the implications. Either that, or they do understand, and simply don't care.

Then, of course, there's the drivers ahead of these people, and sometimes, you'll see this driver suddenly decide to go into the manners-teaching business. They understand the principle I just outlined in the above paragraph, and they're annoyed that the person behind them can't follow this simple logic. So they tap their brakes, the way you're supposed to when dealing with a tailgater, or do some crazy maneuvers designed to mess with the person who wants them to get out of their way.

These are just a couple of examples. Both of these people might not be suitable for some particular job role involving certain kinds of co-workers. It really depends on the job. If you see how they conduct themselves on the road (and if they don't know they're being observed), you get a pretty good sense of who they are as a person.