What is Walter trying to say when he refers to African Americans as "the world's most backward race of people"? Does he seriously believe this?

Jr. is
depicted as a desperate dreamer who is fed up with his current occupation and desires to become
a successful businessman. Walter Jr. dreams of using Mama's insurance money to invest in a
liquor business, in an effort to eventually become financially stable. However, Mama anddo not
support his dream, which pushes Walter Jr. to the edge.

During a
conversation with Beneatha, Walter Jr. criticizes her for wanting to use...