Labrador Retrievers descend from the St. John's water dogs of Newfoundland and were refined in Britain into gun dogs that retrieve game from land and water. The dense, water-resistant double coat, thick otter tail and webbed toes all come from that job. Labs come in black, yellow and chocolate, and dogs from field lines are often leaner and more driven than those from show lines.
Many Labs are sociable, eager to please and happiest around people, balls or water, which is why the breed is so common in family homes and as guide dogs. Adolescence can last until two or three years old, so a young adopted Lab may be bouncy and chewy for a while, while many adults arrive calmer. Each dog differs, and age and history matter as much as breed.