Beneatha experiments with different identities as all young people do. At this point in the novel, she is interested in her African identity, something which she thinks George, as an "assimilationist," eshews (which he does). This is why Asagai has so much appeal to her for he represents that new (or original) identity in that he is an educated man from Nigeria, having a tribe to claim as part of who he is. The contrast between George and Asagai represents a theme in the novel concerning what direction the Younger family should go as they move toward the future. Indeed, Walter Lee's chief dilemma is discovering who he is, finding an identity as a black man in a society that denigrates that identity. Langston Hughes' poem, which the title of the play alludes to, engages this topic through the metaphor of a dream.
George is wealthy and college-educated, but Beneatha feels that his values are superficial. The differences between them are illustrated in his negative reaction when he seas Beneatha dancing in Nigerian dress - he thinks she is "eccentric" and she calls him "an assimilationist". Beneatha has high aspirations and confidence that she can achieve great things. She wants to continue with her schooling and become a doctor. Because of her personal ambitions, not only will she not marry George, she may not marry at all.
Beneatha does not want to marry George because he is full of himself and does'nt cares about other people feelings. eg. when Beneatha dressed in the Nigerian clothes, he thought that she was eccentric, tell me now thats not a nice thing to say about an abitious person like Beneatha.