What I suspected. Actually, Japan has been number 1 for a while in social ranking, only recently superseded.
I guess it is correctly shown. I have indeed very high containment values and people are even enthusiastic in some of my provinces. Probably, because they don't know different (as it happened in real Tokugawa Japan!)...
In the beginning I thought social ranking was a gauge of how advanced is the social fabric of a country according to "Western" standards (no child labor, elected officials, social security, etc). But it seems, correctly actually, that it depends on how happy are the citizens of a nation, even if they have a ruthless dictator on top.