Like people, VC firms can be introverted or extroverted. And "there are cliques among venture firms," Miller adds, "like there are in many markets and many business areas."

The most connected firms in Activate's map? InterWest Partners, Canaan Partners, Alta Partners, Morgenthaler Ventures, SV Life Sciences Advisers LLC, and U.S. Venture Partners.

Here's one detail:

And here's another:









Miller is quick to caution against reading too much into the maps themselves. "Can I state that every connection we've mapped here is one that's of major importance? No," he says. "But it's highly likely that these connections are meaningful" -- not only because a capital investment is almost always also a social investment, but also because a link itself can be its own data point in the wacky world of start-up industry. "Connections matter," Miller says. And analyzing them can help us appreciate, from a social perspective, "how organizations work, how organizations make decisions -- and, in this case, how organizations invest."





He's got research to back him up. Activate Networks builds its connection-mapping technology off of network science , the intriguing and increasingly popular academic field that applies quantitative approaches to social dynamics. Researchers like Nicholas Christakis at Harvard, James Fowler at UC San Diego, and Rob Cross at UVA are applying network thinking not just to digital social networks like Facebook ... but also to their analog counterparts: companies, teams, investment firms.





The real value of social mapping, Miller argues -- whether you're talking about hospital org structures or corporate supply chains -- is the invitation it offers to tease out the implications of the connections it reveals. It's only a little bit interesting that Morgenthaler is connected to Alta. It could be very interesting, though, to find out how Morgenthaler is connected to Alta. And how their link resembles the connection between, say, InterWest and Austin Ventures. And what might it mean that the most connected firms in Activate's map generally specialize in IT and medical science?





If VCs are cliquey, in other words, it's worth wondering how they're cliquey. Do the Mathletes and the jocks ever hang out? What happens when student government and the drama club get together? Where, in this ecosystem, is the line between cooperation and competition? "By using a network approach, you begin to see things that aren't accessible just by looking at lists or by looking at spreadsheets," Miller notes. "You begin to see connections in a way that's somewhat difficult to see using other approaches."

We want to hear what you think about this article. Submit a letter to the editor or write to letters@theatlantic.com.