Propogation:

[denny]

http://www.guardian.co.uk/crime/article/0,2763,1542032,00.html

Comments

[valkyriekaren.livejournal.com]

There was an experiment done recently (I can't find the reference, but I think it was in New Scientist, and someone linked to it at the time - zotz, was it you?) in which they had someone 'collapse' in a public place. In one scenario they had someone planted at the scene to go to his assistance; in the second they didn't. In the first scenario, once other passers-by saw that someone was assisting, they also came forward to offer help. In the second, they tended to hang back and wait for someone else to intervene, or even walk right past.