Last week, I started my last quarter at the Stanford Graduate School of Business. I love this quarter’s classes and want to share my learnings.

Think about your last day at the office. You walked by hundreds of different people. Some colleagues, some strangers Some smiling, some frowning. Some intimidating, others warm and welcoming.

Every single time you interact with another human you have decisions to make. Do you make eye contact? Do you hold eye contact? Do you smile? In last week’s class Acting with Power at Stanford Business School, we learned the consequences of non-verbal communication on interpersonal interactions.

During class, we were split up into two groups and stood at opposite sides of the room. We then had to walk around the room for 30 seconds, just like you would walk around an office, a party, or the streets of New York City.

There was a twist. One group had to act high-power (dominant and confident) by making eye contact, holding it for as long as possible, and keeping their heads completely straight. The second group had to act low power (submissive and deferential) by making eye contact for an instant and then looking away, bowing their heads downwards, and touching their faces and hair.

When I was in the high-power group and crossed paths with someone low-power, it felt incredible. I would make eye contact and hold it, and the other person would drop their eyes and look at the ground. It made me feel confident and happy. I even felt my walk change to a swagger. I could have kept going through that part of the exercise forever.

When I was in the low-power group and crossed paths with someone high-power, it felt terrible. Everyone else seemed so cocky and smug – even arrogant – and I had to look away the moment I made eye contact. It made me feel insignificant and looked down upon, purely based on nonverbal communication. Even though these folks were classmates and friends, the feeling of having to yield eye contact and bow my head felt really awful.

This was such a unique experiment (Give it a try sometime!). Here is what I learned.

1. Confident body language leads to confidence, not just the other way around
During this exercise, my confidence level dramatically changed based on my physical behavior. When I was maintaining eye contact and keeping my head up, I felt confident. When I was quickly looking away and putting my head down, I felt like a failure.

My mood and confidence really changed based on how I was acting, based solely on small changes in body language. Next time I’m feeling down or demoralized, I will try simply acting confident to bring my mood around.

2. We’re always on stage
The premise of Acting With Power is that great leaders spend much of their time acting. Celebrities, CEOs, politicians – they all feel the same day-to-day sadness, anger, and depression as any other humans. But often they must put on a face to avoid showing these feelings to the world.

What this exercise showed me was that, even in a simple interaction crossing paths, we are subconsciously being judged. Sometimes authenticity is important. But often, it is important to act like we’re on a stage: projecting confidence even when we don’t feel confident.

3. Confidence can easily be seen as arrogance
When I was in the high-power group, I felt really happy and confident. I don’t think I was being arrogant; in fact, most of my other classmates at Stanford are far more impressive than me. But my behavior and body language may have made me seem arrogant.

Similarly, in the low-power group, I knew my classmates were not actually arrogant. But being in a low-power role, and not feeling any sympathy or caring, made me think of them as arrogant. Confidence can easily be interpreted as arrogance when it’s not coupled with some level of empathy and connection.

Out of all my classes, this one resonated the most. I’ve started noticing eye contact everywhere.

Next time you lock eyes with a passing stranger, what will you do? Maybe you should wink.