* Tolkien's Descriptions: Tolkien frequently describes hobbits as having "thick, curly hair" in various shades of brown. This is simply part of their physical description, contributing to their cozy, down-to-earth image. He doesn't delve into the *why* of this feature.
* Emphasis on Nature and Earthiness: Hobbits are strongly associated with nature and a simple, agrarian lifestyle. Curly hair can be seen as a natural, unrefined feature that fits with this theme. It contrasts with the more elegant and refined Elves, who often have long, straight hair.
* Possible Genetic Factors: It's possible that curly hair is simply a prevalent genetic trait within the hobbit population. Given their relatively isolated communities, certain traits could become more common.
* Symbolic of Homeliness and Simplicity: Curly hair, in some cultures and contexts, can be seen as a symbol of warmth, friendliness, and a lack of pretension. This aligns with the hobbits' values of comfort, good food, and close-knit communities.
Ultimately, the exact reason for hobbits' curly hair is left to interpretation. It's likely a combination of Tolkien's aesthetic preferences, his desire to create a distinct and relatable people, and the overall thematic elements of the story.