Chimamanda Adichie is an accomplished novelist and essayist from Nigeria. Her most famous work is Half of a Yellow Sun which is an incredibly well written novel, involving an intricate narrative of the Biafran War in Nigeria in 1967.
In the clip above Chimamanda Adichie speaks about the danger of a single story, which means the need for multiple strands of narrative, or stories when attempting to describe something. She explains that stereotypes can be cruel and misleading because they only tell a single story. This can apply to race or any stereotype or preconception.
The media can portray black men for example, in a negative fashion, but of course not all black men indulge in negative practices. Chimamanda is asking us to not to speak in terms of black and white but be able to articulate the grey, to explain the duplicity or multipicity of stories or descriptions. She is telling us to up our storytelling game so peolple don't have to read in between the lines.