The lines between states and even countries are pretty arbitrary: The ties you have with people 50 miles away aren't going to be too-much affected by some imaginary line drawn up 200 years ago. What if you could remap the United States -- not by geography, but rather social ties?
MIT's Senseable City Lab has done just that, by analyzing mobile-phone calling patterns across the country. By looking at calls between cellphones, they've revealed states and cities that are closely connected -- and similarly, regions which aren't nearly as closely connected as you'd think. Here's their main result, color-coded by regional affiliation:
You see all sorts of super-states emerge: Arizona and New Mexico are closely bound, as are Western Pennsylvania and West Virginia, The Carolinas, Louisiana and Mississippi, Alabama and Georgia, New York and New Jersey, and all of the New England states.
With the biggest states, it's something different. California really is split into two distinct regions: Northern and Central California, and Southern California, which is more closely aligned with Nevada and Western Arizona.
You might think something like that would happen in Texas, with several sub-regions clustering around the big cities of San Antonio, Dallas, and Houston. (Think of how different San Antonio and Houston are, culturally and ethnically.) But they managed to cohere into one connected region. But Texas really is like its own country, as Texans say it is -- It's not strongly connected to any of the states around it.
That's relatively rare: Only a few states, such as Colorado, Ohio, and Indiana, are marked by such insularity. And in the case of Ohio and Indiana especially, you could argue that those states stand somewhat removed from their neighbors because of old North/South divides dating from the Civil War; these were transition states that straddled the divide, and remained culturally distinct as a result.
Which brings us to the weirdest example of the lot: Florida and New York. Where most of the ties seem to stem from geographic proximity -- and generations of ties spreading out to places close by -- New York and Florida are the only two strongly connected states that are physically separated. Chalk it up to the fact that New York is the most populous cold-weather state -- and the fact that Florida is dominated by retired out-of-state immigrants.
But where things get really interesting is when you look at the absolute call volumes:
You'll notice here that the big cities draw visible connections to other big cities across the U.S. You can see thin purple strands linking Chicago with Seattle, Phoenix, and New York; you can see Miami sending linkages to cities all along the eastern seaboard.
You can drill into that trend by searching on the county-by-county interactive map. You've got to wonder if, amid all this city-to-city commerce, you're seeing an urban/rural divide that is the true invisible barrier in our country.[The map of connections with New York shows robust big-city connections all across the country]
For hours of fascinating data, check out the Senseable City Lab's interactive map, which lets you type in zip codes and see a heat map for every city.