It's no secret that cats and dogs bring joy to the lives of many people. But now, scientists have found that cortisol - a chemical produced in our bodies when we are stressé - lowers when humans interact with these furry friends.

A popular practice at universities is to introduce therapy dog sessions for stressed-out students during exam times to help them feel at ease. This research is the first to study the impact of dogs and cats on la gestion du stress in a non-laboratory setting.

"Just 10 minutes can have a significant impact," said Patricia Pendry, an associate professor in WSU's Department of Human Development. "Students in our study who interacted with cats and dogs had a significant reduction in cortisol, a major stress hormone."

The study, which was published in AERA Open, involved nearly 300 undergraduate students, who were just about to take their final exams. They were randomly divided into four groups.

The first group received hands‑on interaction in small groups with cats and dogs for 10 minutes and were allowed to play with the animals as they saw fit. To demonstrate the effects of different exposures to animals, the second group observed other people petting animals while they waited in line for their turn. The third group watched a PowerPoint presentation of the same animals available during the intervention, while the fourth group was 'waitlisted'. These students waited for their turn quietly for 10 minutes without stimuli to distract them and were told they would get to play with the cats and dogs soon.

The experts took saliva samples from the participants before and after their interactions with the cats and dogs. They found that the first group who immediately got to play with the animals had the biggest drop in cortisol levels, compared to the other groups.

"We already knew that students enjoy interacting with animals, and that it helps them experience more positive emotions," Pendry said. "What we wanted to learn was whether this exposure would help students reduce their stress in a less subjective way. And it did, which is exciting because the reduction of stress hormones may, over time, have significant benefits for physical and mental health. There does seem to be something specific about the reducing of anxiety from the petting of animals."