You have cited studies that suggest that extreme partisanship might actually be addictive physically. Do you think that John Boehner and Nancy Pelosi are literally getting high from their partisanship?
In accounts of men in battle, there is an incredible adrenaline rush from group-versus-group conflict. The fervor and passion of partisans is clearly rewarding; and if it’s rewarding, it involves dopamine; and if it involves dopamine, then it is potentially addictive. Put that together with the repeated finding that extreme partisans are happier than average and centrists are less happy, and the picture emerges that just as a bird gotta fly, a fish gotta swim — a human gotta be a part of some group competing with other groups to fully flourish and feel alive.