It appears that having either positive or negative outlook is something not just limited to humans. Although dogs may always appear happy and cheerful, findings of a new study suggest that man's best friend can be distinctly optimistic or pessimistic as well.
For the new study published in the journal PLOS ONE on Sept. 17, Melissa Starling, from the University of Sydney in New South Wales, Australia, and colleagues trained dogs to touch a target after hearing one of two different sounds that are two octaves apart. One tone means that the dog will receive milk, considered the reward, while the other means the animal will have plain water. Once the dogs learned what the tones meant, they were presented with tones that are in between the two distinct pitches.
The researchers said that the dogs that kept hitting the target through the ambiguous tones were probably hopeful that one of these touches would get them a reward. Optimistic dogs expect good things to happen and the researchers said that very optimistic dogs may even respond positively to tones that are more like the sound associated with water. Pessimistic dogs, on the other hand, become distressed when they do not get the reward after hitting the target and tend to avoid repeating the task albeit the study says pessimistic dogs are not necessarily "unhappy." These dogs are just contented with the status quo and may need some encouragement to try new things.
"The tipping point shows that dogs are discriminating between tones and supports the hypothesis that they are interpreting some ambiguous signals as signalling a positive outcome and some as signalling a negative outcome as well as pinpointing where that switch in interpretation occurs," the researchers wrote.
Although the study serves as a proof of concept for an apparatus for training dogs and testing their cognitive bias, the researchers said it could help dog trainers select dogs that are best suited to do particular tasks. Pessimistic dogs, for instance, would be a better guide for the disabled because they tend to avoid risks while optimistic dogs would likely do well detecting drugs and explosives.
"This research could help working dog trainers select dogs best suited to working roles," Starling said. "If we knew how optimistic or pessimistic the best candidates for a working role are, we could test dogs' optimism early and identify good candidates for training for that role."
