(chapter 13)As jonas continues his training, he often finds himself angry with his groupmates and his family.. Why?

Jonas sees that his group mates and his family have the emotional maturity of children.  Jonas is experiencing pain, joy, and passion. His friends and family operate on a much lower emotional level. Jonas cannot relate to them anymore. 

Jonas is angry because his family and friends are content with the way they live and they can't see colours. So he's angry because he can't change that for them