(CNN) -- There I was at a long-awaited dinner with friends Saturday night, when in the midst of our chatting, I watched my right hand sneaking away from my side to grab my phone sitting on the table to check my e-mail.
"What am I doing?" I thought to myself. "I'm here with my friends, and I don't need to be checking e-mail on a Saturday night."
The part that freaked me out was that I hadn't told my hand to reach out for the phone. It seemed to be doing it all on its own. I wondered what was wrong with me until I read a recent study in the journal Personal and Ubiquitous Computing that showed I'm hardly alone. In fact, my problem seems to be ubiquitous.
The authors found smartphone users have developed what they call "checking habits" -- repetitive checks of e-mail and other applications such as Facebook. The checks typically lasted less than 30 seconds and were often done within 10 minutes of each other.
On average, the study subjects checked their phones 34 times a day, not necessarily because they really needed to check them that many times, but because it had become a habit or compulsion.
"It's extremely common, and very hard to avoid," says Loren Frank, a neuroscientist at the University of California, San Francisco. "We don't even consciously realize we're doing it -- it's an unconscious behavior."
Why we constantly check our phones
Earlier this year, Frank started to realize that he, too, was habitually checking his smartphone over and over without even thinking about it. When he sat down to figure out why, he realized it was an unconscious, two-step process.
First, his brain liked the feeling when he received an e-mail. It was something new, and it often was something nice: a note from a colleague complimenting his work or a request from a journalist for help with a story.
"Each time you get an e-mail, it's a small jolt, a positive feedback that you're an important person," he says. "It's a little bit of an addiction in that way."
Once the brain becomes accustomed to this positive feedback, reaching out for the phone becomes an automatic action you don't even think about consciously, Frank says. Instead, the urge to check lives in the striatum, a part of the brain that governs habitual actions.
The cost of constant checking
For Frank, constant checking stressed him out and really annoyed his wife.
Dr. Adam Gazzaley, a neurologist at UCSF, sees another cost: Whenever you take a break from what you're doing to unnecessarily check your e-mail, studies show, it's hard to go back to your original task.
"You really pay a price," he says.
Habitually checking can also become a way for you to avoid interacting with people or avoid doing the things you really need to be doing.
"People don't like thinking hard," says Clifford Nass, a professor of communication and computer science at Stanford University. Constantly consulting your smartphone, he says, "is an attempt to not have to think hard, but feel like you're doing something."
How to know if you're a habitual checker
1. You check your e-mail more than you need to.
Sometimes you're in the middle of an intense project at work and you really do need to check your e-mail constantly. But be honest with yourself -- if that's not the case, your constant checking might be a habit, not a conscious choice.
2. You're annoying other people.
If, like Frank, you're ticking off the people closest to you, it's time to take a look at your smartphone habits.
"If you hear 'put the phone away' more than once a day, you probably have a problem," says Lisa Merlo, a psychologist at the University of Florida.
3. The thought of not checking makes you break out in a cold sweat.
Try this experiment: Put your phone away for an hour. If you get itchy during that time, you might be a habitual checker.
How to get rid of your checking habit
1. Acknowledge you have a problem.
It may sound AA-ish, but acknowledging that you're unnecessarily checking your phone -- and that there are repercussions to doing so -- is the first step toward breaking the habit.
"We can be conscious of the habit of checking. We can unlearn its habits," says Sherry Turkle, a psychologist at the Massachusetts Institute of Technology and director of the MIT Initiative on Technology and Self.
2. Have smartphone-free times.
See if you can stay away from your phone for a few hours. If that makes you too nervous, start off with just 10 minutes, Merlo suggests. You actually don't have to stay away from your phone altogether -- you can just turn the e-mail function off (or Facebook or whatever you're habitually checking).
3. Have smartphone-free places.
You can also establish phone-free zones, which is what Frank did to cure his smartphone habit.
"The first thing I did was banish it from the bedroom," he says. "I would have to walk down the hallway to my study to actually be able to see it."
You could also force yourself to stop checking when you're in a social situation, like out to dinner with friends. (Last Saturday night, I shoved my phone way down into my purse where I couldn't see it).
Joanna Lipari, a psychologist who practices in California, uses this strategy when her teenage daughter has friends over.
"I have a rule. Like the Old Wild West which had you check your gun at the saloon entrance, I have a basket by the door, and the kids have to check their phones in the basket," she says. Otherwise, she says, the kids would stare at their phones and not interact with one another.
CNN's Sabriya Rice contributed to this report.