Noble gentlemen and ladies in [Japan’s] Heian period (794-1185) were often remarkably promiscuous. … “Heian society was on the whole governed by style rather than by any moral principles, and good looks tended to take the place of virtue.” … It was, as all this suggests, a rather effete culture. The aristocratic ideal of male beauty—highly perfumed, moon-faced, smooth-skinned, extravagantly dressed—was close to the feminine ideal. A distinct air of decadence during the peak of the Heian period also suggests the approaching end of a regime, a world, in Genji’s words, “where everything seems to be in a state of decline.”

Less than two hundred years later, the self-obsessed nobility of the Heian court, distracted by the rituals and refinements of palace politics, oblivious of the world outside the capital, and mostly bored out of their minds, were overwhelmed by more vigorous provincial clans, notably the samurai, with their warrior codes and martial ideals. But in Genji’s time, the early eleventh century, the imperial capital (today’s Kyoto) still held sway; anyone unlucky enough to live in the provinces was considered too uncouth to be taken seriously. (more)

This seems a familiar history story, that elite self-indulgence and moral decadence causes social decay and displacement. It contributes to the Hunger Games stories, for example. It also seems a common foundation of conservative thought. But, is it true? I ask because I actually do not know. Has anyone done statistical tests on systematic historical datasets to see if decadence actually causes decay and displacement? I could imagine counter arguments, such as that decadence promotes peace instead of destructive war-mongering. So I’d prefer not to have to rely only on a few anecdotes and plausible intuitions.