Dogs have individual levels of sensitivity to change. Some dogs are very alert and aware of all that goes on in their environment and respond fully to every change. These dogs may be easily distracted but are also easily rewarded. Anything from rearranging furniture to using a new air freshener can capture the attention of a sensitive dog. Some dogs respond only to extreme change and even then may attend to the new stimulus only briefly. These dogs can do very well in classroom obedience lessons because they are insensitive to working in a new setting with strangers.  

Additionally, dogs respond to change either assertively or submissively. Assertive dogs lean forward with their tails up, ears forward, and sometimes the fur on their backs and necks stands up. Assertive dogs are not intimidated by travel or strangers. Assertive dogs make good watchdogs because they investigate and are not intimidated by noises or strange objects. Remember that assertive dogs may not ever be aggressive.  

Submissive dogs retreat from change and new situations with tail and ears down. They rarely make eye contact with strangers. Submissive dogs often need encouragement in a standard obedience class because a new place creates withdrawal making learning difficult at first. It is possible to overwhelm a submissive dog with effusive praise as well as with corrections. Dog trainers will often allow a very submissive dog to enroll in a class with young puppies to build his confidence. Remember not all submissive dogs are shy and even shy dogs can bite.

So if you have a reactive or responsive dog who is energetic and assertive, you may have a perfect candidate for police work if the energy can be harnessed by interest in playing ball or tug of war. If you have a submissive, energetic dog who is not very reactive you’ll have an easy time of routine training, even by small children. But there are many combinations of energy level, responsiveness and IQ that can describe a dog and his needs. To fully evaluate a dog's temperament, be sure to read about IQ, energy level and social status.