According to the American Kennel Club, the Cairn Terrier is an alert, active, intelligent, cheerful and long-lived dog breed. They like to dig and need a lot of close social contact with family members.
Cairn Terriers excel in obedience, agility and tracking trials, perhaps due to the breed's working background, and obedience training helps form a bond between the dog and the owner. They should be trained with plenty of positive reinforcement. Cairn Terriers were originally bred to hunt pests on Scottish farms, and they generally get along well with children and other pets.
The most famous Cairn Terrier from popular culture is Toto, from the movie The Wizard of Oz.