<span>u.s. entry into WWI caused industrial psychologists to begin working with the military.After entering into world war-I there is a need for U.S to train their military and develop the army's strength and capability.Psychological research and treatment are important to national defense. Research can show how to improve military training, job assignment and equipment design. Treatment can help personnel cope with stress. Psychologists conduct research on human behavior and treat patients with mental problems. so,industrial psychologists to begin working with the military.</span>
The system of government of the United States, initiated as an experiment in the matter of freedom and democracy in 1776, has given evidence of its admirable resistance and adaptability. Even though the United States is often referred to as a democracy, it is more accurate to define it as a federal constitutional republic. What does that mean? "Constitutional" refers to the fact that the government of this country is based on a Constitution that is the supreme law of the nation. The Constitution not only provides the framework that defines what the structure of the federal government and state governments should be, but also imposes signifi cant limits on the powers of the federal government all of them. "Federal" means that the governments of the 50 states exist alongside the national government. The "republic" is a form of government in which the people hold power, but elect representatives to exercise it.
