"Personnel is policy," they say in government circles, meaning that the kind of work leaders end up accomplishing is deeply shaped by those they choose to carry out their agenda. That's no doubt true in business too, but whom you choose to work with shapes your career in even more fundamental ways. 

"You become the average of the five people you spend the most time with," is another popular saying. Whom you choose to work with shapes not just the work you end up doing, but who you are as a person. We pick up behavior, thought patterns, and even values from those we spend the most time with. And you spend a whole lot of your adult life at work.

So how do you choose people to work with? There are of course a million and one articles out there offering advice on how to hire employees or pick a company to work for. But two interviews from top tech leaders suggest that just one question can help guide your thinking no matter if you're making executive hires or picking your first job out of college. 

Imagine an alternate reality where they're the boss. 

In a recent podcast with MIT computer scientist Lex Fridman, Meta (formerly Facebook) CEO Mark Zuckerberg reveals he's a firm believer in the axiom that you become who you spend time with. 

"I'm always very focused on people, and I think the most important decision you're probably going to make if you're in college is who you surround yourself with," Zuckerberg told Fridman towards the end of the long discussion, Insider reports. "Because you become like people you surround yourself with."

So how does Zuckerberg recommend you choose the people you spent time with? He suggests you ask yourself a simple question: Would I like this person to be my boss? 

This holds true, Zuckerberg explains, whether you're picking colleagues, employees, or even peers for a collaborative project. Whatever your real-life relationship, imagine an alternate reality where this individual is your boss. If that makes you want to run screaming from the room, you might want to run (metaphorically) in real life. 

Zuckerberg explains his philosophy on choosing collaborators in response to a question about how young people can chart a course in life they're proud of, but he goes on to clarify that he still uses the same approach to hiring today. 

"I will only hire someone to work for me if I could see myself working for them," he says. "If it was their company and I was looking to go work somewhere, would I be happy to work for them?"

If you wouldn't work for them, don't work with them. 

He's not the only one suggesting this question. A few years back in the course of a fireside chat with LinkedIn founder Reid Hoffman, Stripe co-founder and self-made billionaire Patrick Collison talked through the three questions he always asks himself before making a leadership hire. Among them was: Is this person so good that you would happily work for them? 

Like Zuckerberg, Collison understands that the best collaborators shape both what we manage to do and who we are. And if you're not willing to concede that they might sometimes know better than you or have good ideas you don't have, then there is no way they'll shape you into a better version of yourself. In short, if you can't imagine yourself being led by someone, then that means you probably don't respect them enough to spend a good portion of your days with them. 

So next time you're deciding whether to work closely with someone, whether that's because you're hiring them for your team, partnering with them on an important project, or even just choosing a roommate or study partner, take a minute to imagine the other person as your boss. If the image makes you uneasy, maybe seek out a different collaborator.