Rick Shenkman is the editor of the History News Network and the author of Political Animals:  How Our Stone-Age Brain Gets in the Way of Smart Politics (Basic Books, 2016). You can follow him on Twitter. He blogs at stoneagebrain. This was cross-posted at Facebook. 

After watching the GOP convention this week I'm more convinced than ever that Evolutionary Psychology (EP) holds the key to understanding politics. It helps make the seemingly irrational performance of the delegates screaming "Lock Her Up" understandable. 

Years ago, before I started researching Political Animals, I would have been stupefied by the frenzy of the crowd. These people after all aren't dopes or low-information voters. Delegates can be presumed to know something about politics.

EP explains what's going on. They aren't thinking. They're reacting. This is what we do when we feel under threat. We need to blame someone when things seem out of whack. So we seize on a scapegoat and dehumanize and vilify them.

All this week we have watched thousands of people demonizing Hillary Clinton.

Partisanship explains why they decided to pick on her. EP helps explain why they don't have to be taught to demonize her. It comes naturally given the circumstances.

Culture can ameliorate our natural responses. As I wrote in Political Animals, that's why we no longer get pleasure watching live cats being thrown into open fires. 

But culture is unlikely to stop delegates at a Trump convention from going crazy because norms of political behavior have been seriously eroded this year. Anything goes! 

Brace yourselves!