Du Bois introduced the idea in the first chapter of The Souls of Black Folk, published in 1903, which drew on his 1897 essay in The Atlantic Monthly. He wrote of a "two-ness": being both Black and American in a country that did not accept those as compatible. He also described a veil separating Black and white America, through which Black people could see the white world, but white people rarely looked back.
The concept explained the psychological cost of Jim Crow. Black Americans had to constantly measure how white people would react, which shaped how they spoke, worked and moved through public space. That constant monitoring is tiring and can distort self-image.
Double consciousness remains one of the most cited ideas in American social thought. It is linked to later concepts like code-switching, where people change their speech and behavior across settings, and stereotype threat. Scholars have extended it to other groups who live between a dominant culture and their own, including immigrants and Indigenous people.