Ignorant is different from stupidity. Many peoples made mistakes because they were ignorant, not stupid. However, the Narcissists are stupid!
Many Western psychological researchers always isolate a few factors to evaluate and explain human behavior and their conclusions are incomplete and arguable.
Human behaviors are driven by their personality, characteristics, and their beliefs. For example, narcissists will take their pride and ego precedence over other values.
The Five Laws of Stupidity
Why Narcissists APPEARS So STUPID (Borderlines and Psychopaths, too!)