Many dog owners believe their pets are able to pick up on their moods, but scientists have demonstrated once and for all that man's best friendcanactually recognizeemotionsinhumans.
Researchers found that by combining information from different sensesdogsform abstract mental representations of positive and negative emotional states in people.
Previous studies have shown thatdogscandifferentiate betweenhumanemotionsfrom signs such as facial expressions. But this is not the same as emotional recognition, according to Dr. Kun Guo, from the University of Lincoln's School of Psychology.
"This is the first empirical experiment that will showdogscanintegrate visual and oratory inputs to understand or differentiatehumanemotion as dog emotion," Kun told Reuters.
Experiments were carried out by a team of animal behavior experts and psychologists at the University of Lincoln, UK, and University of Sao Paulo, Brazil.
They presented 17 untrained domesticdogswith images and sounds conveying either positive or negative emotional expressions inhumans anddogs.
Thedogsused in the testing were unfamiliar with the procedure; avoiding any chance of conditioning. The vocalization sound accompanying thehumanfaces was also unfamiliar.
"We used Portuguese to Britishdogsso they weren't habituated with any words, they weren't familiar with any words. So, we wanted to see if thedogscould assess the emotional content of thehumanvoices and whether they would actually discriminate the emotional information within them," explained Natalia De Souza Albuquerque, a PhD student in experimental psychology.
The results, published recently in the Royal Society journal Biology Letters, found thatdogsspent significantly longer looking at the facial expressions which matched the emotional state of the vocalization, for bothhumanandcanine subjects.
"What we found is that whendogswere hearing positive sounds they would look longer to positive faces, bothhumanand dog. And when they were listening to negative sounds they would look longer to negative, angry faces," added De Souza Albuquerque.
The study shows thatdogscanintegrate two different sources of sensory information into a perception of emotion in bothhumans anddogs. This meansdogsmust have a system of internal categorization of emotional states. Among animal groups, it's a cognitive ability previously only evidenced in primates.
The researchers believe that the ability to combine emotional cues may be inherent todogs. As a highly social species, detectingemotionsinhumans would have helped them in their domestication by people over the generations.
Dr. Kun Guo now wants to conduct more experiments in a bid to better understand how man'scanine companions decipherhumanemotions. "(So) wecansee whetherdogscanuse ahuman-like principle orhuman-like strategy to perceive, understand and respond tohumanemotion," he said.
"If wecanunderstand this, surely wecanunderstanddogsbetter."