What does the movie the Butterfly Effect have with psychology?

I am watching the movie 'The Butterfly Effect" with Ashton Kutcher in psychology class. I have to describe how the movie relates to psychology and I am having a hard time understanding how it does. If you could give me a short summary about how it does that would be great. Thanks.|||things that happened in the children's early life, pattterned they way they were when they grew up.