It sure seems like U.S. Democrats and Republicans are less likely to cooperate than they have been in the past and now, thanks to geographer Clio Andris and her colleagues, we can see that it’s true. They plotted six decades of voting in the House of Representatives, noting the likelihood that their vote will cross party lines.

This is your image of the week:

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Or, here’s the long story short:

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Lisa Wade, PhD is a professor at Occidental College. She is the author of American Hookup, a book about college sexual culture, and a textbook about gender. You can follow her on Twitter, Facebook, and Instagram.