Why people squatting dogs do not chase with this trick can prevent all dogs?

The idiom of “dog on the strength of the people” should be heard, meaning that the dog will be more fierce when the master is around, more bottom, this idiom is a straightforward explanation of the dog is probably the so-called bullying soft and hard, in addition, the dog experience will generally recognize that the dog is a smart animal, if well-trained, can recognize human commands, and think about what is happening. Able to identify human instructions and think about things, then the question arises, the human squatting this posture in the eyes of the dog and what does it represent?      People squatting dogs do not chase because this is the posture of the attack