As a parent, the widely accepted first rule to succeed is to show up, but new research suggests that continuous use of a smartphone in front of a child breaks that rule.

According to LiveScience, researchers found that one in three parents stare at their smartphone while out to eat at a restaurant in the presence of their child. They have suggested that a child is more likely to misbehave when their parent is instead paying attention to their device.

"Caregivers who were highly absorbed in their devices seemed to have more negative or less engaged interactions with children," said lead author Dr. Jenny Radesky, a pediatrics expert at Boston Medical Center, told LiveScience.

Her team's research was published Monday and will appear in the April edition of the journal Pediatrics.

With much attention being paid to smartphones and other advanced mobile devices falling into the hands of children younger and younger, this is a rare study that examines the same phenomenon in adults. The study's objective is to examine how technology and handheld devices affect parent-child interaction and child development.

"Mobile device use is harder to measure than [use of] 'traditional media' like TV, because these devices can be used in so many different ways and are instantly accessible," Radesky said.

The researchers chose dinner time as a study subject because it occurs regularly and encourages face-to-face interactions between parents and children, the Los Angeles Times reported.

"We chose to observe caregivers and children during meals because this is a daily routine in which face-to-face caregiver-child interactions are considered beneficial," Radesky and her colleagues wrote. "It has been estimated that 40% of American meals are eaten outside the home, so fast-food outings probably represent a substantial proportion of family meals."

Anita Kulick, President & CEO of Educating Communities for Parenting, wrote an op-ed for Philly.com that smartphones may be a godsend for adults with their plethora of capabilities, but are a major detriment to parenting. She argued that while an iPhone may be able to connect someone to someone else anywhere else in the world, it makes a parent mentally unavailable.

For the study, the researchers examined 55 family interactions in 15 Boston-area neighborhoods in households with median incomes ranging from $45,000 to $110,000.

While families varied in number of caregivers and number of children, only 15 of the 55 interactions did not involve a smartphone during dinner. Of the other 40, smartphone usage was as short as quickly reading a text to as long as continuous use for the duration of the meal.

"When caregivers were continuously absorbed in the device, some children did not try to get the adult's attention, but many began to exhibit limit-testing or provocative behaviors. In this case, many caregivers used a scolding tone of voice, seemed insensitive to the child's expressed needs, or used physical responses," Kulick wrote. "You don't have to be a child development expert or an anthropologist to see that this study exposes some serious issues concerning parents' overuse of mobile technology and its impact on their children. In some cases, parents were physically near their children, but emotionally miles apart."