On another thread MsJones posted a link to a video lecture dealing with the Lucifer effect which I enjoyed but then found the a Steven Pinker lecture dealing with the myth of increasing violence and had to share it. Reaserch reveals a sharp decline in violence over the millenia, centuries and decades. He postulates why and why we commonly perceive the opposite. Facinating and not too long.
http://www.ted.com/talks/steven_pinker_on_the_myth_of_violence.html