I don't think my hair is as drastic as some of you are describing. But the hair on the sides of my head is 8 inches long, while the hair at my nape and through the back of my head is about 6.
I don't know why this is. I am assuming it's because I have no neck (ehem) so the hair in the back touches/rubs my clothes sooner than the hair on the sides?
My hair in the shorter areas is also a very different texture... while my hair is wavy curls mostly, the hair at my nape and up through the back of my head is coily. And while the ends of my hair in the front and on the sides always seem smooth, the hair in the short hair always feels rough on the ends.
I'm thinking it's a combination of me not doing enough to take care of that area, as it needs more care than the rest of my head, and the hair rubbing my clothes.
I do NOT get much shrinkage, so even when my hair is curly, that area in the back touches the collar of my shirt.