what makes people share articles they read with others?

They’re seeking emotional communion, Dr. Berger said. “Emotion in general leads to transmission, and awe is quite a strong emotion,” he said. “If I’ve just read this story that changes the way I understand the world and myself, I want to talk to others about what it means. I want to proselytize and share the feeling of awe. If you read the article and feel the same emotion, it will bring us closer together.”

http://www.nytimes.com/2010/02/09/science/09tier.html