Smiling human faces are attractive to dogs, thanks to oxytocin.

Smiling human faces are attractive to dogs, thanks to oxytocin. Researchers found that oxytocin made dogs interested in smiling human faces. It also made them see angry faces as less threatening. Associated with affection and trust, the hormone oxytocin is probably a key factor in the interaction between dogs and humans. Researchers in the Canine Mind group showed 43 dogs images of smiling and angry faces on a computer screen. Each dog was tested twice: once under the influence of oxytocin, which was administered as part of the test, and once without oxytocin. The dog's gaze on the images and pupil size were measured with an eye-tracking device. Emotions and attentiveness guide the gaze and regulate pupil size, making eye tracking a window into the dogs' minds.