Dogs possess a remarkable ability to interpret human emotions from facial expressions. Research from the University of Bari Aldo Moro in Italy shows that dogs turn their heads left when detecting anger, anxiety, or happiness, and right for surprise. Their heart rates also spike upon seeing distressed human faces, underscoring the deep bond between dogs and people. This study adds to evidence that dogs process human emotions using distinct brain regions.
Through millennia of close companionship with humans, dogs have evolved specialized skills for communication. Recent research confirms they detect emotional cues in voices, body odors, postures, and faces.
In this experiment, researchers presented 26 dogs with photos of two adults (one man, one woman) displaying six basic emotions: anger, fear, happiness, sadness, surprise, disgust, or neutrality. Images were positioned at the edges of the dogs' vision while they ate.
Dogs exhibited stronger reactions and elevated heart rates to arousing emotions like anger, fear, and happiness, pausing longer before resuming eating. This heightened heart rate signaled increased stress.
Dogs turned their heads left for anger, fear, or happiness, but right for surprise, likely viewing it as non-threatening. These patterns indicate asymmetric brain processing of human emotions in canines.
The findings align with prior studies on dogs and other mammals, highlighting the right brain hemisphere's role in sympathetic responses—like elevated heart rate—for fight-or-flight survival instincts.
