The graphs do not move the way I want

Hello, I have started working in After Effects. I am trying to learn by watching other people edit and doing the same things they do. As I was watching one editor, I noticed that my graphs was not moving like his. When he moved the keyframes in the middle, he did not reverse the graphs on the sides like I did in this video, he just raised the middle line. What should i do to prevent this from effect the rised graphs on the sides ?