Choose carefully when you buy a dog if you want to avoid a later personality clash. Dogs very definitely have individual personalities and can be tested for them.
Prof Samuel Gosling of the University of Texas, Austin, has taken measures of human personality and applied them to a range of animals, principally dogs but also spotted hyenas and cats. His work suggests that the dog pound is probably so full because of a personality mismatch between dogs and their owners.
"People ask the very basic question, does it make sense to talk about personalities in animals," he told a session of the AAAS science meeting under way in Washington DC. "My research suggests that yes, it does."
Human behavioural scientists were frequently hostile to these views, he acknowledged, with claims that his work is "preposterous and scientifically irresponsible". Dog owners and those studying animal behaviour were usually supportive.
"The evidence that dogs and other animals have personalities is as strong as in humans," Prof Gosling said.
Assessment of human personality types is based on a five-point system, he said, including expressiveness; agreeableness; contentiousness or dependability; emotional stability; and being open to new experiences.
He reapplied these to the dog world under four headings: energy levels; affection or affiliation; calmness or anxiousness; and obedience, which is a combination of being dependable and open to new experiences.
Human personality is usually best defined by asking friends to describe a person's traits. He took a similar approach, asking people familiar with the animal to describe characteristics. He then matched these responses against observers who didn't know the dog.
He devised tests for each personality trait: asking the owner to walk away with another dog to gauge emotional stability or hiding a dog biscuit under a carpet to gauge obedience. He found that observations usually matched predictions made by owners.
"You do find breed differences, but there are enormous variations within a breed," he said. It all eventually comes down to the dog's own personality.