Eighteen pet dogs were tested with their owner, and then strangers, talking, pretending to cry, or humming.
Far more dogs come up and touch people when they think they are crying, the study found.
Dogs nuzzle and lick humans they think are in distress, behaving in a submissive manner designed to offer comfort, the Daily Mail reported.
"The humming was designed to be a relatively novel behaviour, which might be likely to pique the dogs' curiosity. The fact that the dogs differentiated between crying and humming indicates that their response to crying was not purely driven by curiosity," explained Dr Deborah Custance of Goldsmiths, University of London.
"Rather, the crying carried greater emotional meaning for the dogs and provoked a stronger overall response than either humming or talking," he said.
Custance and Jennifer Mayer, both from the Department of Psychology at Godldsmith's, London, developed the innovative procedure to examine if domestic dogs could identify and respond to emotional states in humans.
Eighteen pet dogs, spanning a range of ages and breeds, were exposed to four separate 20-second experimental conditions in which either the dog's owner or an unfamiliar person pretended to cry, hummed in an odd manner, or carried out a casual conversation.
Significantly more dogs looked at, approached and touched the humans as they were crying as opposed to humming, and no dogs responded during talking.
The majority of dogs in the study responded to the crying person in a submissive manner consistent with empathic concern and comfort-offering.
The study also found that the dogs responded to the person who was crying regardless of whether it was their owner or the unfamiliar person.
"If the dogs' approaches during the crying condition were motivated by self-oriented comfort-seeking, they would be more likely to approach their usual source of comfort, their owner, rather than the stranger," Mayer said.
"No such preference was found. The dogs approached whoever was crying regardless of their identity. Thus they were responding to the person's emotion, not their own needs, which is suggestive of empathic-like comfort-offering behaviour," Mayer added.
