Lav: After befriending Tulei, the two of them got into a fight with Dusi and his lackeys. Being outnumbered, Guo Jing pull out his dagger to protect himself and his friend. Because of the dagger, the Seven Freaks figured out he is the child they were looking for. The Freaks offered to teach the two boys martial arts, and Tulei happily accepted the offer. But Guo Jing gave a very strange answer: "Mother said that I may not fight with other people. If I learn skills to beat others, Mother will get angry with me." Now, we know that Guo Jing is a very brave boy who actually enjoys fighting, and if necessary he is not afraid to pull a dagger to protect himself. But when the Freaks offered to teach him fighting skills, he says that fighting is not correct… i.e. denying his own nature. For a 6-year-old boy who was almost beaten up by bullies, if offered the chance to become strong, he would most probably not decline… unless he is craven. And we know that Guo Jing is a brave lad. So his reaction is very unnatural.
2. In Chapter 3, it is stated: "Guo Jing has often heard his mother's stories about the brutal Jins… In his little mind is a deeply rooted hatred against the Jins." Please note that Guo Jing was still 6 years old. He has never saw any Jins before, so could he have produced such genuine feelings of hatred? It seems awfully strange to me.
3. In Chapter 4, when Ke Zhen'E asked who killed his father, his reaction was: Guo Jing grinded his teeth and said: "His name is… Duan Tiande!"… Ke Zhen'E deepened his voice and asked: "What would you do if you see Duan Tiande?" In Guo Jing's little eyes sparkled a flame of wrath, and he replied: "I will avenge my father and kill him."
Now, he has never met his father and he never saw Duan Tande killing his father. He only heard stories from his mom. So even though on a rational level he knows he should consider Duan Tiande as an enemy, it is almost impossible for a 6-year-old to have nurtured true emotions of hatred,