Prisons are about as devoid of nature as a place can get. The intensive management unit’s IMU-E cellblock at the Snake River Correctional Institution in Oregon has concrete walls, metal furniture and maximum security cells marked by a single bed, toilet and thick metal door. The 48 men in the isolation unit for inmates convicted of heinous crimes and troublemakers removed from the general population were prone to fights and other shows of aggression, not to mention lots of verbal conflict with prison staff.

Then the staff decided to try a different behavior modification technique: nature videos with scenes of blue oceans, evergreen forests, majestic mountains and fluffy cloud footage shot from airplanes.

The results, according to a new study, were dramatic.

“We found that inmates who watched nature videos committed 26 percent fewer violent infractions,” study author and clinical psychotherapist Patricia H. Hasbach said in a statement. “

Hasbach, who presented the study Friday at the American Psychological Association’s annual convention, conducted written surveys of the inmates. They said they liked videos with beaches, jungles and forest. In interviews, they went on about the animals, colors and, not surprisingly, open spaces, Hasbach said.

The study had its flaws. No one knows how honest the inmate responses were. The presence of the researchers – most of them women – could have lifted the inmates’ spirits. As the year-long study wore on, researchers noticed a 10- to 20-percent decline in video viewing, possibly because there was a limited number of videos.

.More than 90 percent of inmates surveyed agreed “that they felt calmer when they watched the nature videos.” Eighty percent said that the calm was sustained for hours, and nearly 80 percent agreed that when they felt agitated, they thought of the videos to calm themselves.