Francis, inequality -- and two monkeys to make a point

Wrote Pope Francis in a sharp a sharp seven-word Tweet April 28th: "Inequality is the root of social evil.”

His tweet was retweeted nearly 14,000 times by day two. Clearly it was resonating.

So what might be the consequences of greater inequality? Are people likely to sit back and accept it? Will they become increasingly angry? Will unrest and violence follow?

Just how deep is the sense of injustice ingrained within us?

This TED talk might provide some answers.