This fashion trend originated many years ago in the poorer black neighborhoods, where people of African-American descent, most of which had curly hair, used many products to straighten their hair, in order to stand out less, since most Caucasian people had straight hair. The do-rag was used to keep the hair in place while the products took effect, allowing the wearer to straighten their hair while continuing to go about their daily activities.
One of many current fashion trends derived from practices of lower-class members of society used several decades ago.
guy 2: No, my hair is straight enough as it is.
2. some people wear then to look like a thug.
2. ay nigga bro, yo do rag is feddy bro. yo look hella hood.