Primates on Facebook: Several years ago, therefore, Robin Dunbar, an anthropologist who now works at Oxford University, concluded that the cognitive power of the brain limits the size of the social network that an individual of any given species can develop. Extrapolating from the brain sizes and social networks of apes, Dr Dunbar suggested that the size of the human brain allows stable networks of about 148. Rounded to 150, this has become famous as “the Dunbar number”. [...]
So The Economist asked Cameron Marlow, the “in-house sociologist” at Facebook, to crunch some numbers. Dr Marlow found that the average number of “friends” in a Facebook network is 120, consistent with Dr Dunbar’s hypothesis, and that women tend to have somewhat more than men. But the range is large, and some people have networks numbering more than 500, so the hypothesis cannot yet be regarded as proven.
What also struck Dr Marlow, however, was that the number of people on an individual’s friend list with whom he (or she) frequently interacts is remarkably small and stable. The more “active” or intimate the interaction, the smaller and more stable the group. [...]
Put differently, people who are members of online social networks are not so much “networking” as they are “broadcasting their lives to an outer tier of acquaintances who aren’t necessarily inside the Dunbar circle,” says Lee Rainie, the director of the Pew Internet & American Life Project, a polling organisation. Humans may be advertising themselves more efficiently. But they still have the same small circles of intimacy as ever.
Sweet to tweet: Beyond the social or business connections it lubricates, Twitter’s blizzard of short messages has created a new way to catch the mood of the virtual world – and one that works in real time. That, says [Peter Norvig, director of research at Google], may be its most intriguing addition to today’s internet: “The expectation when you come to Google is that you search for things that happened before, not what’s happening now.”
On Twitter, the aggregated voices of millions can be heard in unison. “It’s like saying, ‘Hey, we’re experiencing this together’,” says Mr Norvig. “That fact that I said I was at [President Obama’s] inauguration nobody cares [about] – but if 1m people say they are there, it becomes interesting.”
SIX SECRETS OF AN ONLINE SUCCESS:
Immediacy: Real-time flow of comments and adaptability to mobile handsets makes it more immediate than blogging.
Brevity: Limiting messages to 140 characters makes them easier to produce and easier to digest.
‘Pull’, not ‘push’: The ability of users to choose whose tweets they follow makes it less random than e-mail.
Searchability: Messages can be searched, making the content more accessible than the comments on a social network.
Mixing public and personal: A user’s personal contacts are on an equal footing with public figures.
‘Retweeting’: By copying and retransmitting messages, users can turn the network into a giant echo chamber.
