The Many Faces of You and How To Keep Control of Those Faces - NYTimes.com

It’s a little odd to see your own photo in the “people you may know” box, but I have two Facebook profiles, for work (Claire Cain Miller), and for my personal life (Claire Miller Cain).

Having two accounts allows my friends to see my wedding pictures but not the pitches I get from publicists, and my boss to see links to articles I find interesting but not the photos my friend posted after our vacation in Mexico.

That need to put up a digital wall between work and life is an obvious reason that Facebook recently introduced an easier way to make posts and photos visible only to certain groups. Concern about privacy was one of Facebook’s motivations, but it was also reflecting the way we live our lives offline.

“The problem with traditional social networks 1.0 is all the relationships are flat,” said Charlene Li, founder of the Altimeter Group, which researches Web technologies and advises companies on how to use them. “Everyone is the same level, whether I’m married to you or you’re someone I went to high school with or somebody I met at a conference.”

That online reality does not reflect human nature, said Zeynep Tufekci, an assistant professor of sociology at the University of Maryland, Baltimore County who studies the social impacts of technology.

“Your mom and your boyfriend are rarely in the same room,” she said, “and that’s why Christmas and Thanksgiving are such a stressful time for people, because their worlds collapse. On Facebook you’re in a long extended Thanksgiving dinner with everyone you ever knew, and people find that difficult to deal with.”

Meanwhile, people’s offline social lives have evolved to become more segmented and specialized, said Lee Rainie, director of the Pew Research Center’s Internet and American Life Project. In recent decades, real-life social networks have changed, he said. People now turn to one group of friends for financial advice and another for political or spiritual discussions, for instance.

Facebook’s new ability to split friends among groups takes a step toward addressing this reality. But it still has a lot to learn about the way people live their lives.

Anyone can add a member to a Facebook group, for instance, but only that member can remove herself. So what happens when your sister separates from her husband and he doesn’t remove himself from the family group?

Facebook has received its share of criticism as it prods people to make more information on the site public. Mark Zuckerberg, Facebook’s founder and chief executive, has said Facebook reflects social norms, which are rapidly changing as people become more comfortable sharing more information with more people.

But attitudes toward sharing have not necessarily changed. Instead, people are developing new norms to manage their online lives, said Coye Cheshire, an assistant professor at the University of California, Berkeley, who studies online social intelligence.

For instance, after a party or vacation, people will often e-mail others in the group to find out if it is O.K. to post the photos on Facebook. “People begin to realize the implications of their actions, and that’s where norms get generated,” Professor Cheshire said.

The etiquette may be evolving, but the technology is moving faster than our social practices can adapt. Google plans to introduce social networking tools this fall that it says will become a part of some of its products, like search functions, maps and YouTube.

Perhaps Google has learned a few lessons from its last social tool, Buzz, its answer to Facebook and Twitter. Buzz provided users with a ready-made network of friends automatically selected by the company based on the people each user communicated with most frequently through Google’s e-mail and chat services. But e-mail can hold many secrets, and Google found itself attacked for violating users’ privacy.

In the real world, Claire Miller Cain and Claire Cain Miller are one and the same, but they exist in slightly different spheres.

One will nurse a single glass of wine all night and the other will gladly split a bottle over dinner. One talks mainly about tech, business and journalism, and the other talks mostly about novels, feminism, fashion, hiking and food.

The real world allows me to live these two lives simultaneously. Will the Internet catch up, or will our social and cultural norms eventually adapt? “Even for Mark Zuckerberg, I’m sure he’s not the same way to his mother as he is to his girlfriend,” Professor Tufekci said. “This is Sociology 101.”