Just how badly are we addicted to our mobile devices? It may be even worse than we admit, according to a survey by children's advocacy group Common Sense Media. The San Francisco-based organization bills the study released Tuesday as the first to explore parents' and teens' growing dependence on the tech gadgets that are supposed to empower us.

Nearly 59 percent of parents think their teens are addicted to their cellphones, tablets or laptops -- 50 percent of teens agree -- and 27 percent of parents believe they themselves are addicted. The survey polled 620 parents and 620 teens.

And the survey suggests this behavior is causing friction between parents and children. About one-third of both parents and teens say they argue daily about device use; only 21 percent of parents and 30 percent of kids say that they never argue about it.

"I have these conversations all the time," said Dina Lara, a San Jose mother of two. She recently confiscated her 15-year-old daughter's cellphone for five months. And she limits the screen time for her son in middle school.

Ezekiel Lara, 11, said he plays online games for an hour or two daily. How much would he like to play?

"Maybe two thousand or three thousand hours a day," he said.

It's not just the amount of screen time, but the dull-eyed frequency with which people consult their screens that's troubling. According to the survey, 78 percent of teens and 69 percent of parents check their devices at least hourly, and 72 percent of teens and 48 percent of parents feel the need to immediately respond to text messages.

"I think this is a huge deal for society," Common Sense Media CEO James Steyer said -- in a call from his cellphone while getting off a New York subway. All the people around him, he noted, were glued to their mobile phones.

What has morphed from a handy tool into a work and personal necessity is changing the nature of human interaction and relationships, Steyer said.

"Internet addiction," which encompasses excessive and compulsive tech-related behaviors that produce negative outcomes, isn't a defined psychological disorder. But it has many parents concerned.

"I worry that the phone is attached to her always, always," said Jennifer Carole about her 16-year-old daughter. But there are some advantages. "I know when she's awake in the morning because she starts liking things on Instagram," said Carole, a Santa Cruz-based social media marketing consultant who starts working early in the mornings.

There's no question that children spend a lot of time online: A Common Sense poll conducted last fall found teens spend an average of nine hours daily, and pre-adolescents spend six hours daily, on entertainment media. Those figures don't include time spent doing homework.

In the new survey, 77 percent of parents say that, at least a few times every week, their teens get distracted by devices and don't pay attention to their parents. Similarly, 41 percent of teens say the devices sometimes cause their parents to be inattentive.

And while warnings abound against using phones while driving, adults aren't setting a very good example. More than half of parents admit to checking their mobile devices while driving, and more than half of teens see that behavior.

The Common Sense poll was conducted by phone from Feb. 16 through March 14. It surveyed 1,240 people, half children ages 12 to 18 and the other half one of their parents, both owning a mobile device. The survey has a margin of error of plus or minus 4 percent.

The survey highlighted some apparent contradictions. Despite most respondents saying their families fight over device use, overwhelming majorities -- 85 percent of parents and 89 percent of teens -- insist that use of mobile devices hasn't harmed the parent-child relationship. And two-thirds of both groups say mobile devices aren't allowed at their dinner tables.

Steyer isn't having it.

"I don't believe that," he said. "I think that's wishful thinking."

Michael Robb, Common Media's director of research, said kids may not remember life without devices. "Maybe they don't realize that family life could be different."

On the other hand, the study pointed out the importance of looking beyond mere measurements of time spent on tech. "What looks like excessive use and distraction may actually be a reflection of new ways of maintaining peer relations and engaging in communities," the study observed.

Rebecca Eisenberg, of Palo Alto, views mobile tech as a net plus. She quickly ticked off 13 ways iPhones had improved relations with her two children, ages 10 and 13. She spoke to a reporter via cellphone as she urged her daughter to get off Instagram, searched the house for a water bottle, drove her daughter to soccer practice and told her goodbye.