system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How are the "dark triad" traits in psychology different from each other?

I just noticed that the three traits - psychopathy, narcissism, and Machiavellianism - have many similar effects on behavior. What makes them distinct?
gpt
Psychopathy is a lack of empathy & understanding of how people feel.

Narcissism is placing your own needs & wants over others.

Machiavellianism is lying & manipulating people to achieve your goals.

They're called the "dark triad" because they do so often overlap & feed into each other.  It's easy to be narcissistic if you don't care about how people feel.  It's easy to manipulate people if you feel your needs are more important than theirs.