My family was looking for a small family dog and decided to look at Jack Russell puppies.  We found one on craigslist for the right price - went and met him - and brought him home.  Within the first day, my son had taught him to sit and stay.  You can tell by the knowledge knot on his head that he is very smart.  Jack Russell's make good family pets and are very good listeners and learners.  Since we got him, we have also taught him how to fetch something and bring it back and drop it and how to "sit Pretty'  He is still only four months old and I have a feeling he is going to keep learning...