Yes, psychopaths / narcissists are easy to spot if you know that they exist, and know what to look for.
One caveat is that a person, who is traumatized by being raised by a narcissist will score high on this test. In this case, you need to look at one critical piece. Do you have warm empathy? Do you feel pain when you see others hurting?
And, if you are not a narcissist but were raised by one, you have been traumatized. You have what is now being referred to as CPTSD. Complex PTSD. Complex in that it has multiple sources. And usually its pre-verbal, so the flashbacks are just intense waves of emotions. If you have a narcissist parent, cut all ties with them (going no contact) and find a group for narcissist survivor support.
Im a therapist and came here to say this.