The "challenge hypothesis" first put forth in 1990 in an article in The American Naturalist states that, as an evolutionary holdover from the need to guard mates and progeny, testosterone levels in males are high after vicious competition. Evidence to support the hypothesis has been found in birds. And in human competitors following various types of sporting competitions, elevated testosterone levels have been found--but only in winners. Even politics can provide a testosterone boost, and not only to the direct competitors. For example, right after the 2008 elections, researchers found higher testosterone levels in men who voted for Barack Obama than in men who voted for John McCain.
Now, demonstrating perhaps that the exquisitely sensitive thumb Google has on the pulse of our nation can serve as an epidemiological assay of biomarkers, researchers from Villanova and Rutgers Universities have been following the search terms used in red and blue states. They report that people in traditionally Republican states conducted Google searches for pornography keywords more often after the 2010 midterm elections (widely seen as a Republic victory) than after the 2008 elections (widely seen as a Democratic victory). On the other hand, people from Democratic states searched for pornography terms less frequently after the 2010 Democratic loss than after the 2006 Democratic win. The study assumes a direct correlation between testosterone levels and interest in pornography. It is "Pornography Seeking Behaviors Following Midterm Political Elections in the United States: A Replication of the Challenge Hypothesis," in the May 2011 issue of Computers in Human Behavior.