Scientists have been looking into the relationship between stress and performance for over 100 years, and it has now been observed not just in humans, but also rats, chickens, cats, and dogs. Known as the Yerkes-Dodson law, it says that some stress can be a good thing, but only up to a point. Now researchers have found that the right amount of stress in dogs needed to get optimal performance depends on their temperament.
“When you're taking a test, for example, it helps to be a little bit anxious so you don't just blow it off,” said Emily Bray, who co-authored the study published in Animal Cognition. “But if you're too nervous, even if you study and you really know the material, you aren't going to perform at your best.”
The researchers, from the Duke Canine Cognition Center, devised an experiment to test two groups of dogs. One group was composed of pet dogs, while another was made up of assistant dogs used to help disabled people, specially chosen and trained due to their “mellow” disposition. The baseline temperament for both groups of dogs was measured by counting the number of tail wags per minute, with the service dogs acting “cooler” and the pet ones tending to be more “excitable and high-strung.”
The scientists then challenged each pooch to retrieve a meat jerky from a person standing behind a clear plastic screen. In this situation, the shortest route was blocked, forcing the dogs to go the long way around. They encouraged the dogs in two different ways. In the first, they called the dog’s name in a calm, flat voice. In the second, they called it an excited and urgent manner, waving the treat at the same time.
What they found was really interesting: The optimal amount of stress differed depending on the temperament of the dog. In the first of the experiments, with the calm encouragement, all dogs managed to collect the jerky without a hitch. But when the researchers became enthusiastic and called the animal's name avidly, the urgency boosted the performance of the laid-back dogs, but had the opposite effect on the other group, making the hyper ones crack.
Charlie Brown, the spaniel that just couldn’t cope with the stress. Credit: Duke University/YouTube
In one extreme case, a two-year-old spaniel completely lost it when the encouragement was too much, and simply broke down. “In the first five trials she did fine and solved the puzzle quickly with no problems,” explained Bray. “Then when the high-arousal trials started she choked. She just couldn't figure it out. Adding more excitement pushed the pet dogs over the edge and impaired their ability to perform at their peak.”
The researchers hope that the experiment they devised will help trainers to select service dogs that will perform better under high-stress environments.