Even though I started as an entry-level shop floor employee, my goal was to someday become plant manager. First leadership step? Supervisor. 

I worked hard to make myself the best candidate for that job and in time was told by the department manager that I was "next."

Supervisory openings tended to be very far between, though. When I was offered the chance to start up a small short-run manufacturing facility, I asked my manager for advice. 

"You know I want to be a supervisor," I said, "and I'm worried that taking this role will put me out of sight and out of mind."

He laughed. "Absolutely not," he said. "We already know what you can do. Taking that role will make you an even better candidate." Great. I took the job.

A year later a supervisory position opened up in my "old" department and I didn't get it. I asked the manager what had changed.

After he thought for a while, he finally said, "Actually, I can't think of anything. It just came down to the fact that you weren't around every day."

I was surprised. But I shouldn't have been. 2019 research published in Organization Science shows that "face time helps employees receive better work and leads to career advancement because it is a strong signal of their commitment to their job, their team, and their organization."

More specifically, 2015 Stanford Graduate School of Business research found that remote workers were less likely to get promoted -- even though they were an average of nearly 15 percent more productive than their on-site peers.

So even though we had started up the facility under budget and ahead of schedule, and were already hitting year-three productivity, quality, and cost targets by the end of the first year... it didn't matter. The outcomes were there. The numbers were there.

But I wasn't "there," and someone else was.

Proximity bias -- the tendency for employees in close physical proximity to their colleagues and leaders to be perceived as better workers than those working remotely -- clearly played a role. The results were on full display, but from my "old" department manager's point of view, the work that went into achieving them was not.

He only saw the outcome.

Not the effort.

Which, if some of your employees work remotely -- or even follow a hybrid schedule -- might influence your perception of their relative performance and promotability.

And may influence the opportunities you give them to demonstrate their skills, which further impacts their prospects. See Bob working hard every day and it's natural to assign him an important project -- even though remote-working Nancy is better qualified. See Bob step in to resolve a minor disagreement between employees and it's easy to reward him with an informal leadership role -- even though Nancy's team consistently outperforms every other team. 

The result? A proximity bias ripple effect that rewards presence over outcomes.

What you see is certainly important, but what you get matters most. Make sure you reward -- and promote -- the people who generate results.