During periods following brutal acts of violence or unthinkable devastation, it is easy for our brains to run wild with worry. We worry about our worldly maladies and what often feels like the deteriorating moral fiber of mankind. But as we look down the road towards a new year, there is an argument to be made that things perhaps aren't as bad as they seem. Violence has declined worldwide, so is there any evidence that chaos to some extent is the catalyst for reflection and change? When societies face a crisis, do they increasingly look inward to evolve? Steven Pinker is a professor of psychology at Harvard University and author of "The Better Angels of Our Nature: Why Violence Has Declined."