Imperialism was one of the causes of World War 1. Imperialism means that two countries want to invade the same piece of land as one another. This will result in war because both countries will fight for who gets to take over the other country.
Economic competition was another cause because it was a rivalry of which countries had more profits.
Hope this helps.
(Please mark this as a brainliest answer if it helps you)
Sigmund Freud was NOT a famous economist. He was an Austrian neurologist.
The Tenth Amendment or also referred to as Amendment X in simple terms is "Any power that is not given to the federal government is given to the people or the states." Hope this helps.