What is the duality of experience represented in Irene and Clare in Larsen's Passing?

In Nella Larsen's Passing, the
central characters of the novel Irene and Clare live varied lives even though they are
both African American.  Irene lives in an African American community in Harlem and is
characterized as being proud of her ethnic heritage.  Clare, on the other hand, is quite
fair-skinned, and as a result, has chosen to live her life posing as a white woman.  She
marries a man who is racist and is thus forced to hide her true race and ethnicity.  But
Clare's fiction creates a lonely life, and even though she has slighted her once close
friend Irene, she seeks her help to reconnect with the African American community that
she has abandoned.  But Clare will not step out of her fake "white" identity, and she
does not fully realize the potential dangers that might be caused in her quest to gain
companionship and belonging.  So the two women appear to be polar opposites in terms of
their experience.