A day after writing this particular post, I realized that I had spent too much time doing the academic thing, giving links to more research and such. I failed to put into context why this video and the related research are so powerful. Besides the fascinating results in themselves about animal behavior, there are powerful implications and questions for how we think about ourselves – those fundamental questions about our violent nature, how different we are from other animals, and how we organize ourselves in society. Thankfully David has done that!