Regular people who went undercover at a high school found cell phones pose a bigger problem than adults can imagine - and they've made teenagers' daily lives nearly unrecognizable

A&E

Lina, 23, went undercover as a high school student for a semester for the show "Undercover High."

• Seven young adults posed as high school students for a semester on the A&E series "Undercover High."
• The undercover students discovered that smartphones have completely changed the lives of teenagers.
• Smartphones have become distractions in the classroom and have made problems like bullying and depression worse.

High school isn't what it used to be.

In fact, rapidly changing technology has made the typical American high school experience nearly unrecognizable for the average adult.

No technological advance has changed the game more than smartphones, according to seven young adults who relived their high-school years on the A&E show "Undercover High."

The show follows the adults aged 21 to 26 as they posed as students at Highland Park High School in Topeka, Kansas for the spring 2017 semester. The undercover participants took full course loads, joined clubs, and made friends with students in an effort to see what the lives of teenagers are like today.

Here are seven reasons why smartphones have made high school a totally different place for today's teens.