In the early and mid-1980s, psychologists and wanna-bes flooded the market with self-help books to encourage people to be assertive without being aggressive, to stand up for themselves, to stop acting like wimps in their relationships.

The Jack Russell Terrier never needed such counsel.

The scrappy little dog popularized in television comedies and commercials and on the big screen is the epitome of the assertive and energetic personality: he's bold, brash, vigorous, and supremely self-confident, characteristics that often stun owners who thought they were purchasing a couch potato or a lap dog.

The breed history is wrapped in legend. Named for Parson Jack Russell, a hard-drinking, hard-riding hunter of the 1850-70s, the dog is from the same basic stock as the AKC-registered Wire-haired Fox Terrier1. The parson favored a dog that was bold enough to follow the fox into its earthen den but not so aggressive that it would kill the quarry. His terrier was trained to find and flush the fox for the houndsmen and their foxhounds; it was a flexible dog, able to maneuver in underground dens, mostly white so it could be easily seen, and of the same flamboyant character as the parson himself.

Breed fanciers describe their favorite as a strain of fox terrier, kept pure from the early days, much as fanciers of some hunting breeds have continued field strains of their breeds that today differ from the dogs seen in the show ring.