The form of a human hair follicle is what distinguishes human hair from animal hair. Indeed, it is this form that decides whether or not the hair will be curly. Because the sebum in the hair cannot traverse the length of the hair if the follicles are curved, the sebum never reaches the dry areas of the hair, which is why this is a concern. This means that it is not getting, and is not going to receive, the lubrication it needs to be soft, bouncy, and curly.