The cause that led to the US involvement in WW2 is the Attack of Pearl Harbor by the Japanese<span />
It was harsh on their bodies and the pay wasn't that good
Water fire wind and other stuff
It depends on what career you take on. Psychology is relevant when you're working with people. Since Psychology is a study of the brain and how it works, you can benefit from knowing how certain people think. In marketing, you can better sell your product if you know how the client is thinking. If you go into the medical field, you can know how to explain certain procedures by knowing how your patient is working. So psychology can beneficial in any and all fields of practice. <span />