NOVA science has a very nice video on the recent research (~14 min), which searches for the origin of empathy (whoo-hoo take care with that boxes), and Vilayanur S. Ramachandran speculate it's the development of mirror neurons that was the important evolutionary step setting us apart: It's a system that allowed us to learn fast from others, an the passing on of information didn't have to be hardwired. You can read an essay about his work at EDGE:
MIRROR NEURONS and imitation learning as the driving force behind "the great leap forward" in human evolution
where he calls his research 'the single most important "unreported" (or at least, unpublicized) story of the decade' (not entirely sure though which decade since the website is undated). Well, we will see where it goes. But there seems no doubt that humans are, as Aristoteles called it, a 'zoon politikon', and if I look at modern cities the word TOGETHER can be read imprinted in their skyline, reaching high and higher. And if you sit there in this chair rubbing your nose I can tell I gave you something to think about.
As it is pointed out in the NOVA clip, mirror neurons are a part of our brain that simply doesn't make sense to have if we were alone. I recall an article that I read a long, long time ago in the beginning of internet when people were still surprised about the boom of this feature. You see, skeptics have been saying the internet would be a nerdy thing where a couple of people that haven't seen sunlight for a week pushed data through their network, and there are only oh-so-many people who can get excited about computers. But look at the internet today. It's not about computers, it's about people. It's about communication, it's all about together. That's why it's so successfull. Not because we care about our computer's internal life, but because we care about our inbox, and like to watch others doing stupid things captured on YouTube. Mirror, mirror, ...
And the rise of visual media has definitely boosted our sense of 'connectedness'. I am not sure whether this is an entirely good development - e.g. read Marco Iacoboni's piece on Imitative Violence, which certainly has some truth in it. But whether we like it or not, technological progress has brought the world closer together, for better or for worse. And if we share part of our consciousness through watching, then 9/11 has left a scar on our global neural network.