system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why do different races have different hair textures?
gpt
Hair texture is based on the protein composition of your hair and how those proteins interact together. Proteins are encoded by genetic information, which is hereditarily passed down. I'd assume that at some point in our evolution, as we moved out of Africa, either certain hair types came about that were either adaptively advantageous to the environment or were spontaneous mutations.

(more detailed answer on protein structure of hair) The structural component of hair is basically keratin, which is basically two helical protein loops coiled around each other. At the ends of these keratin strands are "head groups" that can interact with each other and bind these keratin strands together into larger bundles that become the hair you see. Depending on the chemical nature of the head groups, you can have coarse or fine hair, curly or straight etc. For example, more head groups = coarser, thicker hair. That's why, for instance, if you heat up hair you smell it "burning" (heating up the disulfide bridges that form the chemical bonds between the keratin head groups), and you can bend it into different shapes.