Maybe dogs with calm, cool temperaments--the ones that hang out at the beach, fetching surfers' thrown objects with beer-commercial aplomb--perform well under pressure. But for hyperactive dogs, a certain amount of stress can cause cracking under the demand. In this way, they're a lot like people: disposition influences their performance after a certain stress point.

Researchers from Duke University recently published their findings regarding this in the journal Animal Cognition, after having set out to learn whether the conditions that enable certain animals to do their best also depend on the animal's temperament.

In the study, scientists asked dogs to retrieve a jerky treat from a person standing behind a clear plastic wall that was six feet wide and three feet tall. The goal was for the dogs to resist the impulse to take the shortest path to reach the treat. If they did it wrong, they'd bump their heads against the plastic barrier. Instead, they needed to walk around the wall to one of the open sides, as a release described.

The differentiator: in one trial, an experimenter called to the dog in a calm, flat voice. In a different trial, the experimenter waved the treat in the air and called in an urgent, excited voice, the release said.

Scientists tested 30 pet dogs, including a Jack Russell terrier and a Vizsla. Then they tested 76 assistance dogs from a nonprofit organization, the release noted.

Each dog was studied in videos, and the dog's baseline temperament was gauged in terms of tail wags per minute. "The service dogs were generally more cool in the face of stress or distraction, whereas the pet dogs tended to be more excitable and high-strung," said co-author Emily Bray, who was an undergraduate at Duke at the time of the study, in the release.

Both sets of dogs solved the puzzle. But the dogs that were naturally calm and laid-back -- which wagged their tails more readily and quickly -- were more able to stay on task when the level of excitement was raised. They were boosted by the urgency.

For excitable dogs, increasing the stimulation only slowed them down. "Adding more excitement pushed the pet dogs over the edge and impaired their ability to perform at their peak."

Researchers can use the results to develop better tests to determine which dogs will likely graduate from service dog training programs, the release said.