Behavior Modification is the systematic approach to changing behavior. It entails modifying a dog's behavior for the purposes of increasing or decreasing wanted and unwanted behaviors. It looks to change a dog’s reaction to situation, a person, a thing, and animal, etc..
I use classic conditioning, which is a gentle method to alter the behavior of your dog. This method promotes the desired behavior opposed to punishing the bad behavior.
Because fear and anxiety are common causes of aggression and other behavior problems, the use of punishment can directly exacerbate the problem by increasing the animal’s fear or anxiety"
— (AVSAB 2007).