When we were filming for Programme 4 of Virtual Revolution, director Molly Milton and I went through the approximately 5,000 followers I have on Twitter to test (admittedly, only with a sample of me) Professor Robin Dunbar‘s oft-cited Dunbar Number theory. Dunbar proposed that the ’ideal’ number of people in a human community is just under 150. This, he has argued, is the maximum number of people with whom individuals can maintain functional and stable social relationships. The theory is based upon his work with primates, extrapolating the specific number from the size of the animals’ neocortices to ours. More information on this theory is here.

For the programme, we were particularly interested in this phenomenon because the Web has received extensive criticism for undermining social relationships, despite the potential for connectivity that it offers. This has been an accusation levied against it for over a decade in both academic and public discourse. The academic research – particularly the frequently referenced ‘Internet Paradox’ (pdf) article by Kraut et al – has suggested that online relationships do not support positive interactions compared with offline interactions, evidenced by the degree of reported social isolation in the small sample of participants they observed in their 1998 study. Subsequent research (by the same authors) did not support this early research and argued that the original result was due to the number of potential social relations on the early Web.

Publicly, the Web has come under fire most recently from critics like Baronness Susan Greenfield and Dr. Aric Sigman, who have expressed horror at the number of ‘friends’ people claim to have on social networks like Facebook. But what I believe these pundits fail to realise is that the web allows for a diversity of friendship strength; my own research helped to identify evidence of exactly that, using several different context-specific criteria for connection that were considered variations in online closeness. In other words, it’s possible to have good buddies online (e.g., people that you trust) and to have online acquaintances. One interesting recent finding, however, came out of research by Dr. Will Reader at Sheffield Hallam University in Nottingham, who argued that online friends are not truly ‘friends’ unless they are also known offline (see my criticism of this finding (on my old blog) here).

So, Molly and I set out to see whether there was a Dunbar number of close friends who I was connected with on Twitter that cut through the many weak ties that the Web allows me to have.

What we found, I have to admit, disappointed me. It offered support for Reader’s interpretation of his data. Take my Twitter account, for example. At the time Molly & I performed this scan, I had just under 5,000 followers, and only followed 314. Of these, 209 were non-institutions (i.e., not The Guardian’s or the BBC’s feeds). I overwhelmingly reciprocated with people I know offline, and I was able to identify them even thought they used pseudonyms. Most of the people I reciprocated were folks who adopted early, like myself, and most of them were social connections.

We broke the figures down a bit, categorising the people I follow into four general buckets: social, work, institution and unknown. Here’s how it fell:

Institutions: 25
Social*: 103
Work*: 97
Unknown: 16
* if both social/work connection, included in both categories (N=7)

It was pretty evenly split between social and work, and this demonstrates the context of Twitter in my life. It also provided evidence that the Dunbar number is relevant to my twitterverse in each context.

But how did this play out on a different platform? We then analysed my Facebook account.

N FB friends: 563
Facebook crossovers: 102
N Twitter socials in FB crossover: 69
N Twitter work in FB crossover: 36
N institutions in FB crossover: 1
N=5 (work/social)
N=1 (unknown)

I use Facebook fleetingly; usually it’s a bin for my extra emails and occasional (I admit it) self-promotion. Like most legacy social networks, I have accumulated more Friends – who must be reciprocated connections, of course – but a higher proportion of the people I’m connected with I don’t actually know (or remember). Most of the people I do know outside work or technology I know from long ago, whether they’re old friends or old flames. This may be a function of the context and how I view the purpose of Facebook versus the purpose of Twitter.

Ultimately, the exercise was to assess the Dunbar Number in the context of my two primary socially-slanted social networks (versus a social network like Flickr, where I connect with people who’s photos I like, as well as friends and family). What this straw analysis found was that the Number did indeed emerge: despite the largesse of my social connections in these online networks, I have fewer than 150 people whom I really interact with. And most of those are people I know offline.

I’m looking forward to peering into this phenomenon with a larger sample size and more rigorous criteria in the near future.