People fight back because they are angry. Being angry can easily put a person out of character, and lead them to do stupid things. Anger.
can be triggered by pain or frustration, so if a somebody is being pushed around and treated badly they will eventually cave in. A very obvious reason of getting angry is being harassed, people with short tempers will most likely retaliate by fighting. When angry the body goes under a series of changes more sugar an adrenaline flow into the blood stream, the heart pumps faster, blood pressure rises, and muscles tense. All these actions cause the body to go into high gear, which needs to be released with some form of action. Fighting is normally the way this energy is released because people don't know how to release this boiled up energy constructively. If your being harassed you can talk it out with the person or talk to an adult, if you are frustrated you can turn that energy and use it to determine you to work harder to reach your goals. Also anger gives us a quick boost of energy so when angry you can do some physical actions that would be somewhat impossible. All an all fighting is not the way to release this energy, anger is a part of life an makes you more mature and smarter when solved in the right way.
In the movie Terminator 3 people fight back because they are scared. Basically they say the Terminator destroy buildings and do unhuman like things, so the police was scared and took up arms in fright. The female robot T3 brutally murdered people execution style and tossed police men around like rag dolls, and took over police cars by hacking into their systems. Wit T3 the police didn't real get to even shoot at her because she would always do something to kill them first. The police did shoot after the Terminator when he was with John and Kate was in the cemetery, because he was not following their orders and he had a really big Gattling gun.
