A few months ago I was working in Zurich and had several people ask me what in the world was going on with Donald Trump. At that point in time, I was just as confused as everyone else. How could someone known for being a divisive, abrasive, arrogant public figure be appealing to so many people? How could he be making so much progress in the American political system?

After reading Amanda Taub’s article on the rise of authoritarianism in America, it got me thinking about another possible explanation: Donald Trump is appealing to our primitive caveman brains, and a lot of this has to do with the amount of change that’s happened in America, how our brains are hardwired to deal with uncertainty, the fear it creates and how it triggers the body’s stress response.

President Obama campaigned on the promise of change, and there has been a lot of it in the past decade: the passing of many GLBT rights, the economic crisis, the number of mass shootings and the discourse around gun control, civil rights, the resurgence of feminism and the issues around immigration. And let’s not gloss over the fact that President Obama is our first black president. Unfortunately, human beings are not always the best at dealing with change.

Change means the unknown, exerting more energy (mental and/or physical) in creating new habits and routines, discomfort, the possibility of failure, and the repercussions of how it will affect things important to us. There’s also the potential threat to our financial security, opportunity or the status quo. All of this anxiety triggers the body’s stress response and changes how our brains work.

This is a gross simplification of the body’s most complex organ, but the brain has two major components: the earliest portion of the brain to develop was the brain stem and limbic system. This part of the brain is in charge of instinct, survival and emotion. It’s what I refer to as caveman brain, is where our fight-or-flight response originates and is hardwired to seek pleasure and avoid pain. It is very important to note that it does not have the capacity for complex, rational thought. Caveman brain’s job is to be reactive and highly emotional, and it’s kept us alive for millions of years.

The second part of the brain to develop is what is generally referred to as the neocortex. It is responsible for the higher functions of conscious thought, complex social interaction, reasoning and judgment. It’s the advanced portion of our intellect.

When the stress response is activated, our caveman brain takes over control and we have little to no access to our advanced brains.

The reason why Donald Trump’s appeal crosses so many demographic lines - income, age, education - is because it’s not about demographics. It’s about our innate need for safety, security and control. He’s tapping into our caveman brains and promising to do the hard work of correcting what is perceived as too much change, too soon.

Trump operates in a punitive and powerful way, while speaking in simple terms. This is very appealing to our caveman brains. His ideas on immigration and equality coupled with the promise for action are easy ways to get us back into our comfort zones of self-preservation: no one threatening our rights, our territory or our assets. With Donald Trump as a leader, we won’t have to expend precious human energy adapting to these changes, and we won’t have to share our privilege or power with those who are different or have less. Caveman brain in a threatened state is hellbent on protecting itself and its own survival first and foremost.

Trump has rallied together a group of individuals that are focused primarily on themselves, and united them all by fear. An army of people who think: Who cares what’s good for the tribe, I don’t like what’s happening to me.

As a highly developed member of the animal kingdom, and part of one of the most advanced nations in the world, we think we’ve evolved an intellect that affords us a higher level of understanding and thinking. Unfortunately when we experience fear or threat, we’ve only got access to the most primitive elements of our brain’s circuitry.

Instead, we’re reactive and highly emotional. Think about how you feel when you’re discussing politics. What often starts out as a calm, intellectual conversation rapidly turns into a full-body experience. Your heart races, your muscles tense, your blood pressure builds and you’re in full on state of fight-or-flight, and you’d prefer to fight. You’re in the throes of a passionate, forceful argument fueled by anger and indignation.

Which perhaps explains why history often repeats itself: we’re still just a bunch of cavemen, roaming around, ready to spring into action the moment we perceive a threat to ourselves or anything we’ve managed to amass.

And we’ve found ourselves a new king.