Emergent behaviour is defined by the Wikip�a as a complex behaviour which is shown by a collective of simpler agents, where that complex behaviour isn’t defined or coded into any one of the agents, and it can’t be easily deduced from an agent. Michael Crichton uses the example of birds flocking; no individual bird has a n instinct which says “if this and that happens, then flock”. Nor are there leader birds which the others follow. Instead, birds know a collection of simple rules — “stay close to birds near you”, “don’t bump into other birds” — and when you get a lot of birds near one another, all following these rules, flocking just happens. It’s very difficult to tell from the simple rules that flocking will occur, but it does when the birds are viewed as a group; the behaviour emerges from the collective as a whole.
This is obviously a theory which also has relevance to the study of social sciences, which is also partially about studying the actions of a collective of autonomous agents, in this case people.
It’s possible to assert, with some degree of believability, that the propagation of memes is an emergent behaviour from a collective of people; as Baldur notes, it doesn’t just occur among webloggers but in academe as well.
What I’m currently thinking about is whether the blogsphere is susceptible to analysis in this way; sociology is obviously relevant to study of that sphere, but sociology in general doesn’t think in terms of emergent behaviours, because it doesn’t overly concern itself with society as a group of individuals for separate study. (Possibly social psychology does, but I don’t know a lot about that.) It’s possible that the actions of webloggers can be viewed a lot more simply than the actions of people in society in general, because if we look at webloggers qua webloggers rather than viewing them as real people, there’s a distinctly smaller range of actions. For example, if Shelley is right and there’s been (or there is coming) a sea change from the link-comment or Dear Diary styles of weblogging to more thoughtful and considered posting, will there be new and more complex emergent behaviours? Can we predict them? What techniques are there out there to analyse this sort of thing? Could be a whole profitable field of study…