The rise of social networks like Facebook and Orkut allow you to easily follow the happenings of your friends. Twitter allows you to keep track of what they are doing on a real-time basis. But how many people can you truly follow? The Economist has an article which spreads some light on this:
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”. […]
Many institutions, from Neolithic villages to the maniples of the Roman army, seem to be organised around the Dunbar number. Because everybody knows everybody else, such groups can run with a minimum of bureaucracy. […]
[A]n average man—one with 120 friends—generally responds to the postings of only seven of those friends by leaving comments on the posting individual’s photos, status messages or “wall”. An average woman is slightly more sociable, responding to ten. When it comes to two-way communication such as e-mails or chats, the average man interacts with only four people and the average woman with six. Among those Facebook users with 500 friends, these numbers are somewhat higher, but not hugely so. Men leave comments for 17 friends, women for 26. Men communicate with ten, women with 16.
If this is how human beings behave in an informal setting such as a social network, imagine how difficult it is on the mental functions when dealing with several different people at work. Even a big extrovert (shall we dare say “people person”?) only communicates regularly with 10–16 people. I read somewhere that the maximum people one person can manage is seven people at a time. Perhaps that number has something to do with these brain limits.