This is insanely cool. A social-networks theorist has studied the interlinkings between rappers -- and found that their social ties are quite different from other people's. Apparently, the most famous, well-connected rappers tend to avoid one another.

This isn't how things normally work amongst creative professionals. In creative industries, we often see a supercharged version of the "six degrees" effect, because well-known creators frequently collaborate with one another. Their linkages are thus shorter than usual: Studies show that movie actors have only 2.5 links on average between them, versus 3.6 for company board directors and 5.9 for high-energy physicists.

So Reginald Smith at MIT crunched the figures on 30,000 rap songs to see what data he could glean. Sure enough, the artists had close linkages -- it only took 2.9 links on average to connect together rappers together. But then he found an interesting quirk, as news@Nature reports:

Where the rap network differs from these others, however, is in a property called assortativity. This is a measure of how mixed the collaborations are between highly connected and less connected people. In assortative networks, well-connected individuals tend to prefer to make links with others similar to themselves. [snip]

There seems to be no such pattern for rappers. Smith suggests that this might be partly due to commercial competition between successful artists, who are reluctant to lend their cachet to a rival.

But he points out that the aversions of successful rap artists may go deeper than that. Feuds are common in the business, such as that which existed in the mid-1990s between artists signed to Death Row Records in Los Angeles and those with Bad Boy Records in New York. Such rivalries have sometimes led to violence and even murder.

It's also true that hip-hop producers frequently spend their creative time nurturing new talent, which would be a much more benign reason for their lower assortativity. Either way, it's a damn interesting piece of research.

(Thanks to Steve Emrich for this one!)