Divergent I Need help quick?!?!

At the end of Chapter 31, Tobias/Four suggests that one thing that unites Tris and himself are their fears...her "six" and his "four"? What are Four's fears and what are Tris'? Do their fears share anything in common except perhaps that they are fears? What do you think about this Four's comment about their fears uniting them? Do you believe that people can be united by their common fears? Do you think that such emotions as fear are stronger than those associated with pleasure or love? Why or why not? Would you be more likely to yield to fear than to love?