I’m full of empathy because I barf when you do. But not always.

There was this one time, as the plane from Tampa landed in Kansas City, and daughter Courtlynn decided to spew. I had the barfbag ready and carried it off the place like a pro.

Then there was this other time, and me and Amy and Sorenne and Katie were driving back from Florida to Kansas, and after 24 hours in the car with only an hour to go, Sorenne spewed all over the back seat.

And then I pulled over and barfed.

According to NBC News, if seeing someone hurl makes you gag, too, and then launch into a puffed-cheek, double-hands-to-the-mouth, chest-heaving dance before you either toss your own cookies or scurry safely (and dryly) away, well, we owe you a compliment.

People who feel the urge to barf when witnessing another person throw up are both compassionate and highly evolved, say two medical experts on the stomach-turning topic.

“There’s good news and bad news about why upchucking causes other people in the immediate vicinity to upchuck,” said Amy Morin, who teaches psychology at Kennebec Valley Community College in Fairfield, Maine and works a licensed clinical social worker.

“The good news is, if it happens to you, it means you have empathy,” Morin said. 

In human brains, scientists have discovered “mirror neurons” that cause some people to feel the same emotions as others around us. This explains why you might tear up when you see someone in the room cry.

If that sounds like you, when you see someone vomit, your brain feels empathy and causes you to actually feel that disgust with the other person, and so the food in your gut wants to come out, explained Morin, who also writes for about.com at discipline.about.com.

“The bad news is, there’s not much you can do about it. If you are prone to upchucking or gagging at the site, smell, or mention of vomit, your brain is likely fairly hard wired to react by doing so,” she added.

This wretched reaction is, in fact, still laced into our brains from ancient times – as a pure survival instinct, said Dr. Jennifer Hanes, an emergency physician at Northwest Hills Surgical Hospital in Austin, Texas.