stephen pinker said: "The decline of killing and cruelty poses several challenges to our ability to make sense of the world. To begin with, how could so many people be so wrong about something so important? Partly, it's because of a cognitive illusion: We estimate the probability of an event from how easy it is to recall examples. Scenes of carnage are more likely to be relayed to our living rooms and burned into our memories than footage of people dying of old age. Partly, it's an intellectual culture that is loath to admit that there could be anything good about the institutions of civilization and Western society. Partly, it's the incentive structure of the activism and opinion markets: No one ever attracted followers and donations by announcing that things keep getting better. And part of the explanation lies in the phenomenon itself. The decline of violent behavior has been paralleled by a decline in attitudes that tolerate or glorify violence, and often the attitudes are in the lead. As deplorable as they are, the abuses at Abu Ghraib and the lethal injections of a few murderers in Texas are mild by the standards of atrocities in human history. But, from a contemporary vantage point, we see them as signs of how low our behavior can sink, not of how high our standards have risen."