Shaina Meyers has always believed that long nails don’t belong on small fingers.

“I have incredibly small hands and little fingers, and they just don’t look right with really long nails,” she says. Her paws are so petite that they’ve earned her the nickname “Carnie Hands” from her friends, and Meyers, Omaha, Neb., senior, swears that even her 10-year-old cousin has hands much larger than her own.

Meyers says her desire to keep her fingernails short led to a lifelong habit of biting and picking at her nails. The subconscious behavior began when she was young, and the bitten, rigid and weak nails crowning the tips of her small hands today are evidence of an unrelenting attack.

More than one third of children under the age of 10 bite their nails at some point, says Robert Steele, a pediatrician at St. John’s Regional Health Center in Springfield, Mo. Although the number of nail biters generally decreases with age, those unable to quit by adolescence or adulthood continue to struggle with the habit as they grow older.

“Pretty much every time I start biting, I try to stop and stick my hands in my pockets,” says Sean Henning, Leawood senior. “But it’s frustrating because I’m doing it subconsciously.”

For adults to stop biting their nails, Steele says they have to consciously recognize the behavior as it begins to develop. In Stop Your Nailbiting! Permanently, author Gilbreth Brown defines nail biting as a two-step process that nail biters need to understand before they can permanently surrender the habit.

The physical act of nail biting and picking comes only after what Brown calls the “secondary habit,” when nail biters methodically scan their fingertips for any tear, flaw or irregularity in the skin or nail. Imperfections give nail biters the justification needed to begin the “primary habit,” which Brown defines as “the habit of periodically and habitually biting, picking, tearing, ripping, gnawing, gouging, licking, smoothing, pruning or performing any other self-inflicted action targeted toward mutilating the ends of one’s fingers.”

And these actions are not solely confined to the fingernail. Often, Brown says, the entire fingertip is targeted during heavy picking. Besides short and disfigured nails, consequences of nail biting and picking can include painful swelling, bleeding and infection.

Despite the sore and aching aftermath of an intense biting session, battered and tender fingertips find their way back to the mouths of habitual nail biters. Constant biting weakens the nails and makes disfiguring them again fairly easy, Meyers says, reinforcing the behavior.

A tense ending to a sporting event is often described as a “nail-biting finish,” and any pictorial depiction of an individual gripped with anxiety usually includes a person with his hand to his mouth, nervously gnawing at the ends of his nails. Steele says there isn’t one specific cause behind the behavior, but that nail biting is often a convenient way to pass times of stress or boredom. “When people are passively monitoring something and can’t sit and watch, they turn to bouncing their knee, twiddling their thumbs or picking at their nails,” he says. Other reasons people bite their nails include overactive grooming habits, self-punishment and parent-child modeling.

Henning remembers watching his mother bite her fingernails before he picked up the habit as a child. He also says that when he works with his hands as a bike mechanic during the summer, he has little time to bite his nails. “It’s when I’m sitting in class and not being asked questions or not answering questions and I want something to do with my hands — that’s when I start biting,” he says.

Because little research has been done on nail biting, the causes behind the behavior aren’t fully understood. So if the clicking sound coming from the nail biter to your right sends shivers up your spine, wait a second before giving them the evil eye and remember that your hair twirling, ear lobe tugging or foot tapping could be equally aggravating to the person sitting to your left.