Teens shuffle into the classroom, backpacks slung over shoulders and earbuds dangling out of sweatshirts. Jokes among friends fly as the students plop into desks arranged neatly in rows.

The instructor in the green shirt jingles a small silver bell. The room grows still. Murmurs fade.

The polished wooden floorboards creak amid the pressure of shuffling feet. A portable fan whirs. Then the room turns quiet.

For the next 20 minutes, there is no lesson, no talking, no laughing, none of the bustling sounds of a high school classroom on a weekday morning.

The boys and girls close their eyes and allow their bodies to relax. Some rest their heads on the palms of their hands. Most close their eyes.

These Gage Park High School students are participating in Quiet Time, a transcendental meditation program that aims to help them with the stress and pressures of life inside and outside the brick walls of the Southwest Side school.

This happens twice a day. Every school day.

The program is run by the David Lynch Foundation, a nonprofit organization co-founded by the movie director, and is being studied for its effectiveness by the University of Chicago Crime Lab. Researchers are examining whether the meditation program offers tangible benefits for teens at a school where 98.3 percent of students are considered low income.

“In their neighborhood, they are fighting to survive, literally,” said Jose Morales, who teaches English as a second language. “And they need an alternative to the violence.”

Quiet Time was one of three programs — out of 200 applications — selected by the Crime Lab when it asked for proposals to help address youth violence in the city. The Crime Lab awarded a $300,000 grant to the foundation to launch the program in Chicago Public Schools because of its goal to address the effects of toxic stress on young people. Quiet Time also has been implemented in San Francisco, Los Angeles and New York City.

The Crime Lab believed the program showed promise because of its demonstrated success in the other cities, Executive Director Roseanna Ander said, and it was helpful that it was cost-effective to launch and had the ability to be rigorously evaluated.

“It helps you to slow your mind,” said James, 17, a senior at Gage Park. The Tribune agreed not to publish students' last names at the school's request. “It helps you to slow down and focus.”

Before taking part in the Quiet Time program, James said, he was quick to anger and often was arguing and fighting. Now, James said, he is calmer and thinks about how to react when someone says something objectionable or he finds himself in a stressful interaction. “I feel it can help people in school and out of school and with everything you do in life,” James said after a restful meditation session.

Initially, James thought the program was going to be an opportunity to nap, but after learning how it worked, he gave it a try and was surprised at what he found. James has even had friends who do not attend Gage Park ask him about meditation, and he's trumpeted its benefits.

In addition to Gage Park, Quiet Time has been rolled out at Daniel Hale Williams Preparatory School and Bowen High School. The meditation program is voluntary. In order to study its effects, students at the beginning of the school year were randomly selected for the program, while others participate in a general quiet period that serves as a control group. At Gage Park, the entire school goes quiet at the same time twice daily, even though only about half the students are meditating.

Staffers with the foundation teach the students the basics of transcendental meditation at the start of the semester, learning how to focus on a phrase or mantra that allows them to rest their minds. While students meditate, there is no music or background sound, and no chanting, singing or specific instruction. Students attempt to clear their minds and let stress fade away. The meditation, the foundation says, does not involve any religious or philosophical component and is taught to students by certified instructors.

Bob Roth, chief executive officer of the foundation, said transcendental meditation is a state of “restful alertness.” It helps kids relax and aids in learning readiness, he said.

“You just can't keep jamming more facts and figures into a kid's brain,” Roth said. “The message to the child is ‘quiet is important.' ... Quiet Time gives the child a tool, a technique that's very simple,” Roth said. “The stakes are very high. We're in danger of losing an entire generation of kids because of the stress.”

U. of C. researchers are studying the effects of the meditation program by observing in the classroom and analyzing data from CPS and the Chicago Police Department. Researchers will collect grades, test scores, attendance records and disciplinary records, including in-school infractions and out-of-school arrests, or whether students were victims of crimes.

The program began in pilot form in the fall of 2015 and will continue next school year.

It was funded by two anonymous donors and the Pritzker Pucker Family Foundation. The MacArthur Foundation is funding the evaluation.

The Crime Lab and foundation selected schools in areas of the city with high homicide rates and with particularly disadvantaged students. A gathering of data will demonstrate the program's overall effect.

The plan is for the program to be expanded and studied in an additional two or three CPS schools, and U. of C. researchers are going to study the program in New York. One of the goals, Ander said, “is to learn which programs work the best in what context and for which students.”

Gage Park Principal Brian Metcalf said the Quiet Time program has yielded immediate results for students and staff. Suspensions are down, Metcalf said, and a recent round of SAT prep scores showed improvement. Teachers, he said, see improvement in students' behavior and ability to concentrate in class.

Morales, the Gage Park teacher, said, “As a teacher, I've seen a transformation of how we, how I, handle conflict in the classroom.”

Morales, 57, initially was skeptical of the meditation program, doubting that such a practice would make much difference at a school such as Gage Park. Morales said he thought program and school officials were “naive” to believe the program would resonate with students, and he said he expressed his reservations.

But slowly, Morales began to see the upside with students, and himself.

Morales said the practice has helped him in the work setting and during the slog of his commute. Stuck in traffic, he no longer curses at other drivers or stresses about congestion, trying to bring his mind to a calm place.

For students, the program helps teens learn to manage stress, cope with anger issues and navigate the perils of everyday life, teachers and staff said.

“I was a real belligerent person and a hothead before, and it's really calming and releases stress,” said Rakiha, a Gage Park sophomore. “It relaxes me, and it opens my mind up.”

Another participant, Breana, didn't know what to think of the program initially but then blossomed during the sessions.

“When I first heard about it, I said, ‘What is this? What are we doing?' ” Breana said. “When you really get into it, I really got some stress off my mind. I really think before I do certain things.”

The students are not the only ones participating. Inside the third-floor classroom, Morales and biology teacher Shameka Jones sat by the windows, eyes closed, faces softening.

Jones said she has battled anxiety and depression, and the Quiet Time program has been a welcome addition to her school day.

“The first time I did it, I felt so relaxed,” said Jones, 36. “I felt ready to work more than I ever had. I feel like I can handle any obstacle. I don't have to feel the weight or stressfulness. I can feel OK, and I can approach situations and deal with them. ... It was like a vortex in my brain opened up and allowed positive energy in.”

poconnell@chicagotribune.com

Twitter @pmocwriter