Quark: I think I figured out why Humans don't like Ferengi.

Sisko: Not now, Quark.

Quark: The way I see it, Humans used to be a lot like Ferengi: greedy, acquisitive, interested only in profit. We're a constant reminder of a part of your past you'd like to forget.

Sisko: Quark, we don't have time for this.

Quark: You're overlooking something. Humans used to be a lot worse than the Ferengi: slavery, concentration camps, interstellar wars. We have nothing in our past that approaches that kind of barbarism. You see? We're nothing like you... we're better.

DS9, The Jem'Hadar (1994)