What is Bigger's main fear in Native Son?He has multiple fears, however, yet explain his main one.

I think that there are many reasons that could be used to
explain his main fear, as the subtext of the question indicates.  I think that White
society does seem to be Bigger's predominant fear.  There is a fear of what White
society thinks of him when he cannot say anything to Mary's mother about him being in
the room.  His fleeing from White society's police and the relationship and perception
he has about White society all result in his fears of it.  His fears are certainly
justified and well grounded in what is the reality for someone in Bigger's condition. 
Yet, they are fears and Wright might be using this to explore how African- Americans,
particularly African- American males, perceive White society.  The odd element in this
configuration is that Bigger does believe in the American Dream.  The belief that Bigger
can actually find his own niche in the American Dream is one that inspires him to get
the job that enables him to be near Mary in the first place.  The fear of White society
is enhanced by his desire to be close or to be a part of it.  In this light, one can see
his fear as a twisted condition of reality within it.