Evolutionary anthropologist Robin Dunbar has a famous theory that the number of people with whom one can maintain a close relationship is limited to 150 by the size of the neocortex, the part of the brain used for conscious thought and language. 
 
 The Internet has made it quicker and easier to connect with far-flung acquaintances, but Dunbar says it's impossible to overcome that basic brain programming. 
 
 With high rollers on Facebook boasting up to 5,000 "friends," digital friendship has become increasingly indiscriminate. And that keeps some people from feeling comfortable sharing the more intimate details of their lives. 
 
 That's the motivation behind Path, a San Francisco company that is offering a more exclusive social network. Path, whose service launches Monday, bills itself instead as a "personal network." 
 
 Dave Morin, formerly an executive at Facebook Inc. and Apple Inc., and Shawn Fanning, co-founder of Napster, are betting that people crave more private interaction with a much smaller social circle: Path lets each user designate only 50 friends. Morin estimates that, based on Dunbar's research, 50 is "roughly the outer boundary of our personal networks." 
 
 "You usually have about five people whom you trust most, 20 whom you consider your BFFs that you hang out with all the time and about 50 or so who are your personal network," said Morin, co-founder and chief executive of Path. "Path is built for that." 
 
 Not long ago, many were leery of using their real names or divulging personal thoughts, opinions or feelings on the Web. But social and media-sharing tools such as Facebook, Twitter, LinkedIn and Foursquare have ushered in an era of online openness in which people routinely broadcast snippets and snapshots to their friends and followers. 
 
 As Facebook pushes users to open up to an ever wider social circle, however, some are holding back more information. If their network contains even one person they do not trust, people tend to clam up, Morin said. 
 
 Path, which is designed to help people capture moments and share them only with people they trust, isn't meant to replace Facebook or other social networking services, but rather to "ride alongside them," he said. "The idea here is that you always control who you're sharing with and you can tell the story of your life to your closest friends and family." 
 
 Path users tell that story through photos. You snap pictures and post them; over time, the series of snapshots creates a "path" of your life. Photo sharing is already one of the most popular features on social networking sites. The rise of photo-centric networks such as Path and DailyBooth reflect a shift in how young people communicate, using photographs as a simpler, faster and more expressive medium. 
 
 The way Path works: When you sign up for the service, you can find your friends through e-mail addresses or phone numbers. You take photos with an iPhone and post them, with tags for people, places and things. You can control which of your friends see any particular photograph. You also can see who has looked at any particular photo. And you can view your friends' locations on a map of the world and click to see what they have posted. If you don't want notifications about a certain friend, you can "pause" that person. 
 
 Path is focused on building its product for mobile phones. Currently, it offers a free iPhone application. Apps for Android and BlackBerry phones are on the way. Users can look at their networks through the Path website but must use an iPhone to add pictures. 
 
 Altimeter Group analyst Jeremiah Owyang said people are increasingly interested in making some of their updates more private on social networks. But, he said, those people can use existing filtering features to do that. He also noted that, on average, Facebook users have fewer than 150 Facebook friends — still within Dunbar's number. Path may offer a compelling proposition, but it's difficult for a new social network to gain traction, he said. 
 
 Path has recruited high-profile investors, including actor Ashton Kutcher and angel investor Ron Conway, and high-caliber talent, including the engineer who built the photo application for the iPhone. Morin said he believes people will be won over by the ability to be themselves and share candid, unconstrained moments with loved ones. His sister, for instance, gets to see snapshots of his everyday life that help her feel more connected to him: his feet in happy socks, the mocha he is drinking and views from his morning run. 
 
 "She tells me, 'I feel like I am seeing your life through your eyes,'" Morin said. "These are not moments that matter broadly, but they matter to the people close to you. Shared experience is the foundation of happiness in relationships. Oftentimes, experience is seeing." 
 
 jessica.guynn@latimes.com ||||| Today we are proud to launch The Personal Network. Practically all of us carry a camera phone, and our photos tell the stories of our lives. Starting today, we hope that Path is the place you will always feel comfortable being yourself and sharing the story of your life with your closest friends and family via the photos you take every day with your mobile device. 
 
 We’re launching first on the App Store on iPhone. If you do not have an iPhone, you can still register and check out Path through your browser. 
 
 So, what is Path? 
 
 Path is the personal network. A place to be yourself and share life with close friends and family. The personal network doesn’t replace your existing social networks – it augments them. 
 
 Path allows you to capture your life’s most personal moments and share them with the 50 closest friends and family in your life who matter most. 
 
 Because your personal network is limited to your 50 closest friends and family, you can always trust that you can post any moment, no matter how personal. Path is a place where you can be yourself. 
 
 Capturing 
 
 Capturing a moment on Path is simple and contextual. Simply take a photo with your camera on iPhone and add context around that moment in the form of tags for people, places and things. These tags provide 3 types of context which we think help capture a moment. 
 
 Think of it as a place for the memories along your path through life. 
 
 Sharing 
 
 On Path, you always control who you are sharing your personal moments with. We know that if you are sharing with a single person you do not trust, you will not feel comfortable sharing. So we’ve built the personal network model to keep you in control, always. 
 
 We chose 50 based on the research of Oxford Professor of Evolutionary Psychology Robin Dunbar, who has long suggested that 150 is the maximum number of social relationships that the human brain can sustain at any given time. Dunbar’s research also shows that personal relationships tend to expand in factors of roughly 3. So while we may have 5 people whom we consider to be our closest friends, and 20 whom we maintain regular contact with, 50 is roughly the outer boundary of our personal networks. These are the people we trust, whom we are building trust with, and whom we consider to be the most important and valued people in our lives. 
 
 We’ll help you find those close friends on Path, and we’ll help you share with those who aren’t yet on Path. 
 
 No following, no friending…just sharing with the people who matter most. 
 
 Interacting 
 
 Because Path is a personal network, we will always seek to build features which increase meaning and understanding between close friends. 
 
 To this tune, we’ve built an innovative new feedback feature we call “Seen It”. 
 
 For each moment that you capture and add to your Path, you will see which of your friends have seen the moment in real-time. The idea is that understanding enables trust and storytelling amongst close friends and family. 
 
 We hope you feel like more of your close friends are seeing life through your eyes than ever before. 
 
 Exploring 
 
 Because of the amount of context included in each moment on Path, we want to help you explore and understand both your memories and those of your close friends’ in unique and interesting ways. We have started by helping you see moments on a map of the world. Expect more neat visualizations in the future from us. 
 
 How do I start my Path? 
 
 Path is available from the App Store on iPhone or in the App Store here. 
 
 If you do not have an iPhone, but want to register your username and check out Path on the web, sign up here. ||||| In Other Social Network News. How About Fewer Friends? 
 
 While we all anxiously, or not, await the Facebook announcement on email, another social network is launching today, based on an interesting number. 
 
 Let's start with the number. Robin Dunbar is a British anthropologist and evolutionary biologist. He wrote a paper that lays out how big social networks are among primates, the number usually cited is about 150. That's how big human networks are where everyone knows everyone else. The number, according to Dunbar, is actually a product of neo-cortex size. The number was popularized in Malcolm Gladwell's Tipping Point. And it's all the rage in people making social networks in Silicon Valley. 
 
 But a new company that launches today is focusing on a different, smaller, Dunbar number: 50. That's the number of people you know and trust. And that's the limit on the number of friends you can have on the new social network Path. 
 
 One of Path's founders, Dave Morin, was once at Facebook. But he says that Facebook has just become too big, too public, and that you really don't want to share everything with hundreds of friends. From the LAT: 
 
 "You usually have about five people whom you trust most, 20 whom you consider your BFFs that you hang out with all the time and about 50 or so who are your personal network," said Morin, co-founder and chief executive of Path. "Path is built for that." 
 
 Path launches today with an iPhone app that allows you to share and tag photos with your 50 friends. It lets you limit who can see the photos (no more embarrassing mumbles about why Jim didn't get an invite to the party), and you can tell who has looked at the photos. 
 
 It's still a question though whether Path, or another similar service, can convince people that overshare on Facebook that their cat obsession really should be limited to people who do actually care.
– If you were moved by Jimmy Kimmel's recent push for a National Unfriend Day, you should be glad to hear this news: New social network Path launches today, and it limits you to your nearest and dearest 50 friends. Path's limit is in keeping with the work of evolutionary anthropologist Robin Dunbar, who famously theorized that you can only maintain close relationships with 150 people—and of those, you probably only trust 50 of them, NPR notes. Developed by a former Facebook exec and a Napster co-founder, the photo-centric service's founders believe that Facebook users aren't divulging everything to their 5,000 friends, and will share more if their number of connections is limited—though they're not pitching it as a Facebook replacement, but as something meant to "ride alongside" other networks. It launches as an iPhone app that allows users to find friends using email addresses or phone numbers, then snap, post, and tag photos to create a "path" of your life, the Los Angeles Times reports.