Public speaking: the bane of anyone’s existence, no matter how comfortable you feel in front of crowds. There’s just something about standing in front of a room of people watching you expectantly that almost compels you to embarrass yourself. As soon as you face your audience, your mouth suddenly becomes dry, your palms are sweating, and you can hear your heart beating through your chest. Your voice, out of nowhere, develops a strangely high pitch, and you’ve now forgotten your starting point despite practicing your presentation at least 50 times.

But why do we always seem to have this response when we are placed in front of our peers? What is it about public speaking that paralyzes us with fear?

In Gizmodo’s new view, they seem to find a solution. When we are faced with speaking in public, our fear centers in the brain are triggered in a way that initiates our fight-or-flight response. Although this isn’t a near-death situation, our body has a hard time distinguishing the difference, and only responds to the increasing sense of dread we are feeling deep down in our bones.

Before we know it, thousands and thousands of years of evolution starts to kick in before we even manage to open our PowerPoint. The brain responds to the outside stressor by activating the amygdala to send a message to our adrenal glands. Adrenaline, the hormone secreted from the gland, flows to our heart and our lungs to help blood and oxygen pump quicker throughout our bodies. Most of this blood is sent to our muscles, preparing us to respond to the situation by, you guessed it, fighting or fleeing.

It is this indiscriminate reaction that causes you to freeze up in front of your coworkers. So next time your boss tells you that you dropped the ball, you can thank evolution.