Flexibility of a society can be described in (at least) two ways below.
One is whether a society can support those who went outside of the framework of a society – in this case they were originally born within it, but prefer to spend time beyond the framework. For example, in general, students are demanded to live in a school where the life is standardized. But a handful of them have different perspectives, they can expand them on their own, and can get our of the framework intellectually. Famously, Edison dropped out from primary school and he left the great inventions in our world.
Another case is whether we can comprehend people coming from outside of framework – this is different from the one explained above since the example of this case is for instance, migrants originally living in the place outside of framework and entering into it. The flexibility here means not whether we can accept the entering of migrants physically, but the flexibility of a society that for example in school, whether school can flexibly respect people having different sense of values like religions, customs, and others. In school where Japanese students are mostly organized in the same standard, whether they can flexibly respect the students coming from different context.
Recommended article regarding the related topic
L'histoire de mes pensées 