Parents don’t need a poll to tell them their teenagers are addicted to smartphones. After all, smartphones are a permanent fixture rather than accessories on the visages of kids of all ages these days.

Even so, polls move these everyday observances from anecdotal to official problem when the numbers tilt in that direction — and a Common Sense Media poll hit full tilt.

The fact that 59 percent of parents said their teens were addicted to mobile devices was not surprising. However, the fact that 50 percent of teens admitted they were addicted was shocking.

While parents feel uneasy about their kids constantly being tethered to a device, most are not sure what real harm tech addiction does to teens. It turns out that it has multiple ill effects.