Study Says Petting Dogs or Cats Can Reduce Stress A study commissioned by Washington State University has found that comfort from an animal can have a “significant impact” on stress levels. In as little as 10 minutes, interacting with animals was found to cause a significant reduction of cortisol, the body’s main stress hormone. The study, which involved almost 250 college students, examined four different groups. One group was allowed to interact with the cats and dogs for 10 minutes, while the other three groups either observed or remained isolated. Researchers then took saliva samples from the participants and found that those who directly interacted with the animals had less cortisol. Patricia Pendry, an associate professor at WSU, believes the study shows “exciting” results. Patricia Pendry, via The Ladders