One of the contributors, psychologist Steven Pinker, points out that sadism and violence in human beings has shown a steady decline (with a few zigzags along the way, obviously). Thiis is backed up by this statistic from another contributor, curator of the TED Conference Chris Anderson:
Percentage of males estimated to have died in violence in hunter gatherer societies? Approximately 30%. Percentage of males who died in violence in the 20th century complete with two world wars and a couple of nukes? Approximately 1%. Trends for violent deaths so far in the 21st century? Falling. Sharply.
I’ve singled out these two contributors, but really, the whole thing is worth reading. I will return to some of the other points raised in the responses in future – there’s so much there!
Warning – if you’re easily upset by cruelty you may want to give the Pinker article a miss, as he mentions (in the first paragraph) some rather distressing stuff that used to happen.