According to a new study by the Canine Science Collaboratory at Arizona State University and published in the journal Behavioural Processes, dogs would rather be petted than receive vocal praise.

For the study, researchers observed 42 shelter and pet dogs as they interacted with two people in a room. While in the room with the animal, one human would pet the dog while the other would use verbal praise. Then researchers watched to see who the dog would spend more time interacting with following the petting and praising.

The second part of the study involved 72 shelter and pet dogs that were put in a room with one person. The shelter dogs interacted with a stranger while the pet dogs worked with their owners. Researchers then recorded the interactions between the human and the dog for eight three-minute sessions. According to the study, each session included instances of either petting or praising the dog, doing both or not interacting with the dog at all.

At the end of the study, co-author Dr. Clive Wynne, professor and director at the Collaboratory, said that the dogs preferred to interact with the humans that were petting them. What researchers found most surprising was that the dogs showed the same amount of interest in the people who verbally praised them as the humans who paid them no attention.

“I was surprised that when only one alternative was available, dogs still did not engage with the human for vocal praise,” Dr. Erica Feuerbacher, study co-author and assistant professor of anthrozoology at Carroll College, told The Huffington Post in an email.

The reason dogs prefer petting may be because the contact can reduce a dog’s heart rate and blood pressure.