In the fantasy genre, there is a recurring trope that the "civilized" folk - often white, male dominated - are dishonest, politicking, backstabbers, while the "savage barbarian" is blunt, honest, and thoroughly confused by the strsnge behaviours of the civilized folk and lies. Does this have any basis in history, or is it just authors using common themes? When did this trend first occur?
The trope is popping out as early as ancient world (Tacitus "Germania") however it was truly born in the era of Enlightenment with Rousseau as it most notable proponent. In his Discourse on the Origins of Inequality Among Men he glorified what he called State of Nature that was corrupted by... civilization essentially.
THE first man who, having enclosed a piece of ground, bethought himself of saying This is mine, and found people simple enough to believe him, was the real founder of civil society. From how many crimes, wars and murders, from how many horrors and misfortunes might not any one have saved mankind, by pulling up the stakes, or filling up the ditch, and crying to his fellows, "Beware of listening to this impostor http://www.constitution.org/jjr/ineq_04.htm
He was not the first to express such ideas, however he was most influential in spreading them. So influential in fact, that phrase "noble savage" is often attributed to him.
On the other hand same Enlightenment gave exact opposite take on the issue, championed by Hobbes.