how does chris show two distinct sides of his personality

Chris seems eager to meet and connect with people on his journey yet he abandons his own family. Chris was close to his sister Carine. By the time that McCandless is a senior at Emory, he lives monastically, has driven away most of his friends with his intensity and moral certitude, and barely keeps in touch with his parents. Chris seems to abandon people once he connects with them. He even does this with people on his journey like Ronald Franz.