Why do most dutch people have blond hair?

Native Dutch have blond hair because they have genes responsible for blond hair. Two blonds have a high change making blond haired kids. A blond an a dark haired person usually make non-blond childeren. Genes responsible for blond hair are also found in other west and nordic civilizations (Germany, Denmark, Sweden, Norway, Finland, Iceland, Scotland, Ireland, England). You might say most germanic speaking countries tend to have most blonds and light eyes.