Divergent Series Complete Box Set question

Tris is stronger by body because she could resist the death serum and fight death. Tobias is stronger by mind he is stronger on the inside because with a dad you are afraid of and with a mom who you think is dead and then find out she is alive and to lose the only person who you thought was your family isn't easy my friend.

Tris is a pure Divergent but Four is damaged. She is entirely unaffected by the sick ways of their experiment known as Chicago. Four is not.