Sometimes, you can take a great and insightful idea or discovery and distil it to it's simplest form, and it tells a great story. Other times, in distilling it down to a simple form (often a newspaper headline), it becomes something different.

A story that's currently going through the "report, recycle, repeat" process of what we call "news" is the story about how your brain can't handle all your Facebook friends; any more than 150 "friends" is just a meaningless figure, because our brains can't handle that many.

That's the short version of the story: OMG: Brains can't handle our Facebook friends.

A slightly longer version (less headline-friendly) would explain that Robin Dunbar came up with a theory some years ago, based on observations of social units of primates and the relationship between the size of the social groups and a particular area of the brain, concluding that the human brain is suited to groups no bigger than 150 people. Later this year, he plans to publish the results of some newer research which will show that social networks like Facebook don't affect this number; even if you have 1,500 friends, an analysis of traffic shows that you maintain the same inner circle of about 150 people.

Two big questions come to my mind about those findings. Firstly, how does something like Facebook change those relationships? My own Facebook friends who post regular updates get more of my attention, and I know more about what's happening in their lives than those who post less frequently. Some who post incessantly will get ignored or even "defriended." Then there are the friends who either aren't using Facebook, or aren't very active— who miss updates, event invitations and other activity that's happening on the site. I simply can't believe that Facebook hasn't changed the way that friendships— even within those inner circles of 150— are functioning.

But a different spin on the same story (and I think a more interesting one) is that the fact that our brains "can't handle it" is the point.

I wrote something a couple of months ago (as a response to a blog post by Seth Godin) that seems to be just as applicable to this new study.

The point of Dunbar's Number is that it's about closed groups; 150 people who all know one another, and know how everyone relates to everyone else. That's thousands of relationships that you're constantly keeping track of; who is close friends, who doesn't get on, who has a bit of history that you shouldn't bring up in front of their partner?

Something interesting is going on with new digital social networks (whether that's a network on Facebook, Xbox Live, MSN, Twitter, LinkedIn etc. etc. or simply the list of contacts in your mobile phone or email application) that is very different, and it's not about what's happening in the middle of your network, between you and your immediate family and closest friends.

A great piece of research by The Guardian looked into the way "word of mouth" messages move from person to person, and the types of connections between people that best help to facilitate it. They found that the "weak ties" are particularly interesting because they help you to pull in information from lots of different sources, and they let you spread information out across wider groups of networks.

Which is obvious, when you think about it. If there's a closed group of 151 people, each of whom only speak to one another, then they are never going to pull in anything new— other than whatever comes from traditional, broadcast media. Everyone is only connected (through one step of separation) to 150 other people.

But if you take an equivalent group of 151 people and "sacrificed" one of them, so that each member of the group now has enough spare "brain power" to be acquainted with someone from a different group; all of a sudden, that group of 150 people now has access to the ideas and information coming from 22,500 different people. Each person still has 150 friends, but they are now connected (weakly) to a whole new set of networks. When each of those networks is also connected— even through a single person— to a different network, then something incredible comes out. Quite quickly, everybody becomes connected to everybody else.

Now, factor into that equation the fact that the "sacrifice" idea is clearly ludicrous, and the fact that everyone is still somehow managing to keep track of everything in the media; the stories about Brad Pitt's relationship, Miley Cyrus' boyfriend, Madonna's latest comeback, Peter Jackson's new film, U2's next tour, J.K. Rowling's next book, the Arctic Monkey's single, the new family in Eastenders, the new shadow cabinet, the new American president, the latest Al Qaida bomber, etc. etc. etc.

These names, identities, characters, faces and stories don't somehow diminish our ability to maintain friendships. (At least, I don't believe that they do.) We don't have a dozen or so friends fall out of our brain if we follow the main characters while watching the Lord of the Rings films, or struggle to maintain real world relationships while watching The Wire DVD box sets. So why would some extra characters on the edges of our social networks be impossible to keep track of?

In the Phaedo, Socrates argued that the use of paper would destroy the human mind; people would write things down instead of remembering them, and rely on other people's writings in place of "true" learning through experience. Since then, a similar argument has been made about every new media or communications tool. (Just look at last week's report about computer games causing rickets— apparently because by playing computer games, gamers aren't going out and doing exercise. I'm eagerly awaiting a follow up study finding the same thing about reading books being bad for your health…)

I used to be able to remember all my closest friends' phone numbers. Today, I can't— over the last ten years, I gradually relegated that job to the address book in my mobile phone. Now I can just about remember my own mobile number, my wife's and my parents. Over the course of my life, I've become increasingly reliant on a number of tools that do essentially the same job; address books (made of paper), business card collections, or personal organisers.

Until recently, the sole purpose of these tools was to keep track of the contact details of people so that I didn't need to rely on my memory if I wanted to recall them. But more recently, the tool for remembering has become embedded into a tool for communicating; mobile phones, email address books, and Social Network profiles.

A few years ago, my wife helped to organise a school reunion. It took a lot of effort to make the most of all those individual connections— lots of people were still in touch with a few people, so there were "chains" of connections that had to be exploited to spread the word— some phone numbers, some email addresses, some friends-of-friends. It all took a lot of time and efforts. But just a couple of years later, everyone was on Facebook; doing the same thing would have been a completely different exercise. (Just a couple of clicks of the mouse to set up an event and send out invitations.) The point is that networks like these aren't about the kinds of connections where people know how everyone is still connected; who still knows who, and everyone contacts one another at least once a year. They are about the connections out on the edges; the phone number you haven't called since you left school, the email address you haven't mailled to since you left your last job, or the address you haven't posted to since you met someone on holiday. Technology is (still) changing the way these social connections work.

(As an aside, I suppose I should confess here; I haven't read the Phaedo- or any of Plato's other works. I first read about this argument that Socrates made online some time ago, and most recently on the Made By Many blog. But this just shows how our relationship with information is changing as books, records and news becomes digitised, fragmented and networked. When I was at school, a big deal was meant about how History was no longer about memorising dates, but understanding what happened and how. In maths lessons, we weren't just allowed to have calculators— we needed them. In my A-level Physics exams, we had booklets of the important equations we needed to understand. This is a continuing trend; I don't need to know something if I can access that information at any given moment. But the counter-trend is that I need to be able to evaluate and analyse the information that's available to me, to judge whether on a particular topic, I should trust Wikipedia, Encyclopedia Brittanica, or something on a blog I came across via Google that some random nerd has written.)

The interesting stuff is happening out on the edges. It's the school friends you'd lost touch with who you can now easily reconnect with. And it also includes new "friends"; other people you might want to keep in touch with, or keep track of. That might include celebrities— actors, musicians, politicians, writers, directors, journalists, or any other number of public figures. You might use something like Facebook to follow an abstract concept. Or you might be "friends" with a fictional character; you might choose to use social media to follow characters in a TV show— or an advertising campaign. Or rather than brand spokespeople, you might "friend" (or "fan") a company or a brand itself.

This is something that has a huge impact on business communications— from advertising to sales and marketing, to customer service, advocacy programmes, PR, and even internal corporate communications. And that's why reading anything that talks about how technology and digital media aren't changing anything (especially when it comes from someone as respected as Robin Dunbar— albeit, possibly a distorted or misreported version of his theories) I find it kind of disappointing.

The only reason nothing has changed is because everything is, and always gas been, constantly changing. I think it's essential— not just because it's my job as a researcher in digital media, but as a member of this changing society— that we understand how things are changing as best we can.