What motivated Griffin to change the color of his skin and take on the identity of a black man, as recorded in Black Like Me?
John Howard Griffin started out with the purpose of conducting "scientific research" into the attitudes related to racial segregation for the purpose of writing "journalistically objective articles for Sepia (a popular magazine for African Americans in the southern United States at that time) detailing his experiences." His method of research was based on turning himself into a black man so that he could conduct his research through first-hand experience.
To his surprise and dismay, however, Griffin discovered that racial prejudice was present within his own thinking process.
In the flood of light against white tile, the face and shoulders of a stranger—a fierce, bald, very dark Negro—glared at me from the glass. He in no way resembled me. The transformation was total and shocking.
This discovery was unexpected, and added new dimensions to his learning process. His research became much more personal and the threats and reactions experienced were interpreted differently once Griffin understood he needed to deal with his own prejudices, as well as documenting those he encountered in others.