No, the answer isn’t Illinois.

I’m asking not about location, but about the way you’re being right now. That means the emotion you’re feeling, of course. It’s also the way you’re thinking. How you hold your body. The way you move. Your energy level.

Here’s the big thing about our states. They’re contagious.

Your colleagues, clients, companions, everyone in your sphere is influenced by your state. And their state has an impact on you. So it’s smart to choose your company carefully, isn’t it?

How do you catch someone’s emotions?

You quickly notice their posture, facial expression, the way they move…and unconsciously begin to mirror them. So if they’re frowning and furious, you start to scowl and before you know it, you’re ticked off too.

It happens in a split second. And University of Chicago Professor John Cacioppo says the more expressive someone is, the more likely you are to pick up on what they’re doing and mimic it without even realizing what’s happening.

“The muscle fibers in your face and body can be activated unbeknownst to you,” Cacioppo told US News & World Report. Those tiny muscle movements then trigger the actual feeling by making your mirror neurons fire, creating the emotion just as if you were experiencing it for yourself.

Same thing happens with tone of voice and language. In a conversation, we tend to match the emotional charge of the other person’s words. Especially when those words are negative. “Hate” “Anger” “Sad” – those words carry a lot of energy.

At Oregon State University, psych prof Frank Bernieri says, “Communication requires the matching of specific words and contents so people can understand each other, so it’s easy to see how language could drive this contagion process.” (Gives you pause about all that time you spend on Facebook, doesn’t it?)

You can probably remember hundreds of times when you got caught up in an ebullient colleague’s enthusiasm and your own state lightened up. Or when somebody else’s glum mood brought you down. In fact, the downward drift is more likely.

The experts say negative states are more contagious than positive ones. Because our prehistoric ancestors who were attuned to others’ fear, disgust and anger were more likely to heed a threat and survive.

Now, in the new millennium, seems to me the trick is to get intentional about this very natural, automatic aspect of communication.

So once you decide not to be infected by a colleague or customer’s negativity, how do you protect yourself?

• Pay attention to your own feelings, and when things start to go south, ask yourself, “Is this me – or am I picking up a downer from someone else?”
• Mind your face when you’re around someone who’s angry or depressed. See if you can keep a neutral or pleasant expression. You don’t want to succumb to subtly imitating them and “catching” the state behind the sourpuss.
• I’m a big believer in the power of the imaginary bubble. I’m not kidding. Picture yourself inside a giant bubble so everyone else’s bad vibes bounce back instead of getting all over you. (Beyond warding off negativity, seeing myself in a big pink bubble can make me giggle inside so my mood gets better instead of worse.)
• And you can inoculate yourself against negativity. Maybe you’ve heard Shawn Achor’s Ted talk about how to be happy at work: 1) write an email praising someone; 2) write down three things for which you’re grateful; 3) journal about a positive experience for two minutes; 4) exercise for 30 minutes; or 5) meditate for just two minutes.

So we can avoid being sucked into someone’s negativity. It’s also possible to bring them along into your own rosier point of view. How? Remember that people are more likely to “catch” a state from someone who’s quite expressive.

The bigger your smile, the more you gesture, the more grounded you are, the more likely it is that your positive energy prevails. The person you want to influence begins to mirror you—and their state lightens.

That can have big business benefits, right? Imagine your clients wanting to be around you, looking forward to your conversations, basking in your uplifting aura.

Okay, that got a little too woo-woo, didn’t it? But I hope you can see the value of warding off negative contagion, deciding what state you want to be in and staying there. And even using your own positive energy to shift their state for the better.

Maybe you’ve observed this emotional contagion in your own work—or in your life! Comment below to share your story.