Study Shows Dogs See the Water Bowl as Half Full…or Half Empty

Just like us humans, dogs can have an optimistic or pessimistic outlook on life, according to a new study published last week in the Public Library Of Science (PLOS).

The research, conducted by Melissa Starling, Ph.D., and a team from the University of Sydney, involved 40 dogs of various breeds and ages. Its purpose was to test the dogs’ judgment bias — “how animals interpret ambiguous signals and whether they expect more positive or negative outcomes,” according to the study.

“The remarkable power of this is the opportunity to essentially ask a dog, ‘How are you feeling?’ and get an answer,” Starling said in a press release.

Similar to Ivan Pavlov’s famous bell-ringing study that conditioned dogs to drool when they were about to be fed, the University of Sydney researchers used one distinct tone when they offered the dogs water. They used another tone that was two octaves higher when they offered lactose-free milk, considered a tastier treat.

When the dogs became used to those two tones, the researchers started using nine alternative tones. If a dog didn’t respond to any of those nine tones, he was considered to be a pessimist.

“Pessimistic dogs appeared to be much more stressed by failing a task than optimistic dogs,” Starling said. “They would whine and pace and avoid repeating the task, while the optimistic dogs would appear unfazed and continue.”

Most of the dogs in the study turned out to be optimists, but Starling said it’s to early to assume that’s true of the general dog population.

According to the study results, we may incorrectly peg our dogs as being optimistic or pessimistic, when they’re actually the opposite.

“There was a tendency for owners and trainers to overestimate the optimism of dogs belonging to pessimistic, moderately pessimistic and balanced groups,” the study reports, “and to underestimate the optimism of dogs in moderately optimistic and optimistic groups.”

Being labeled as a pessimist is not necessarily a negative, especially for working dogs. Because they are less likely to take risks, pessimistic dogs make good guide dogs, Starling said. Optimistic dogs are better suited for tasks requiring tenacity, such as sniffing for drugs or bombs.

Knowing whether a dog is an optimist or pessimist could also be helpful in determining the most effective training method to use.

“This research has the potential to completely remodel how animal welfare is assessed,” Starling said. “It could be used to monitor their welfare in any environment, to assess how effective enrichment activities might be in improving welfare and pinpoint exactly what a dog finds emotionally distressing.”

Photo credits: Noël Zia Lee, hannah k