The Patterjack temperament cannot be predicted in fail-proof manner. Some be more like the Patterdale Terrier while others will favor the Jack Russell but, regardless, they are known for their loving, cheerful-- and, of course, curious personalities that, if not brought up correctly, can manifest as aggressive and stubborn.
This breed is best suited for the experienced owner that is a hunter or active person because the PJ thrives on tasks and "work". It is important to set boundaries and and start training immediately to keep the Terrier "fire" under control. A dominant owner that, most importantly, is firm and consistent will have the most success with these dogs. An untrained, under-stimulated Patterjack can be a nightmare... barking, digging, snapping and showing territorial behaviors; ditto for those that are treated like a baby instead of a pet.
A well socialized Patterjack that has been brought up around children and other pets should make a good family pet. They fare best with older, more respectful children and can usually live with cats. They do retain strong hunting instincts towards small animals so, in addition to socialization, it is advised to keep them leashed outdoors unless inside a fenced area. Energetic and alert, the PJ enjoys hunting activities, patrolling the house or yard, long walks and games with toys.