Why do black men have a crease at the back of the neck of their heads?

The crease at the back of the neck, often referred to as a nuchal line, is a natural anatomical feature found in many individuals, regardless of race. In black men, this crease may be more pronounced due to thicker hair texture and grooming practices, such as shorter haircuts that accentuate the shape of the head. Additionally, genetic factors can influence the prominence of this feature, leading to variations in its appearance among different individuals.