Since Chris is being isolated from his parents and barely have any contact with them, he felt that he would gain their attention by leaving into the wild to keep his parents worried and guessing where he might of head off and why. Chris never ended up having a relationship problem with his sister but only his parents which may the only ones to blame for his actions in isolating himself to the wild.
The second reason why Chris was led to the wild was because of his philosophical beliefs. In the book, Into the Wild, Jon Krakauer stated that Chris did not like the way humanity was living at the time as they stayed indoors for most of their lives rather than enjoying nature and having some outdoor activity. He felt disgusted by people’s way of living and think they should go out more and appreciate nature. Chris’s belief on enjoying nature was compared to another man who had the same belief and ended up dying at a desert like how Chris died in cold temperature. Chris never really had a desire for anything and seemed to appreciate life as it is especially from nature. At one point in the book, McCandless was given the choice to either have a new car or keep his old one. Instead of having a