two causes: And, another cause was the job opportunities. The two causes would be social society and along with social society Eugenics because this set the standards based upon the experiments that were tested of to which society then would judge people based upon these standards and thus, making people believe that one race in inferior to another which would then lead to someone getting the lower bargain of the deal because there is never enough money to go around for everyone. So in a word, Eugenics caused it because people used the ideas taught to them in Eugenics to basically say that it was okay to discriminate. And, also in a sense another cause would be the Jim Crow laws because the people basically could think that if we can get away with discriminating against people in places like school and such what is stopping us from making them move into new areas.
The message of the Harlem Renaissance writers, poets, and artists was that African Americans have talent as well and your skin color does not define what you can do especially when it comes from the standpoint of skill.