response: I don't know where it is most common, but it is common in parts of Europe, the US, and parts of the Middle East.
original_response: Good question, its actually most common in the Western world, especially with europe, USA and even some populations in the middle east
history: I have brown hair and i love other people with brown hair Oh, that's nice. After black hair, brown is the second-most common color. where is it most common?
knowledge: Brown hair is common among populations in the Western world, especially among those from Central Europe, Southeastern Europe, Eastern Europe, Southern Europe, Southern Cone, the United States, and also some populations in the Greater Middle East where it transitions smoothly into black hair.