What it shows is that, as a function of the people a Facebook user actively communicate with, you are passively engaging with between 2 and 2.5 times more people in their network. I’m sure many people have had this feeling, but these data make this effect more transparent.

The stark contrast between reciprocal and passive networks shows the effect of technologies such as News Feed. If these people were required to talk on the phone to each other, we might see something like the reciprocal network, where everyone is connected to a small number of individuals. Moving to an environment where everyone is passively engaged with each other, some event, such as a new baby or engagement can propagate very quickly through this highly connected network.

All Friends: the largest representation of a person’s network is the set of all people they have verified as friends. Reciprocal Communication: as a measure of a sort of core network, we counted the number of people with whom a person had had reciprocal communications, or an active exchange of information between two parties. One-way Communication: the total set of people with whom a person has communicated. Maintained Relationships: to measure engagement, we took the set of people for whom a user had clicked on a News Feed story or visited their profile more than twice.

It is easy to become unsettled by privacy-eroding aspects of awareness tools. But there is another — quite different — result of all this incessant updating: a culture of people who know much more about themselves. Many of the avid Twitterers, Flickrers and Facebook users I interviewed described an unexpected side-effect of constant self-disclosure. The act of stopping several times a day to observe what you're feeling or thinking can become, after weeks and weeks, a sort of philosophical act. It's like the Greek dictum to "know thyself," or the therapeutic concept of mindfulness. (Indeed, the question that floats eternally at the top of Twitter's Web site — "What are you doing?" — can come to seem existentially freighted. What are you doing?) Having an audience can make the self-reflection even more acute, since, as my interviewees noted, they're trying to describe their activities in a way that is not only accurate but also interesting to others: the status update as a literary form.

Laura Fitton, the social-media consultant, argues that her constant status updating has made her "a happier person, a calmer person" because the process of, say, describing a horrid morning at work forces her to look at it objectively. "It drags you out of your own head," she added. In an age of awareness, perhaps the person you see most clearly is yourself.