Fear is primal. In fact it may be one of our most primal emotions. It triggers the fight or flight response in us to avoid dangers by activating the amygdala, which floods the body with adrenaline through the hypothalamus.
This reaction is triggered so fast that we feel fear before the prefrontal cortex, our rational part of the brain, can even process the danger.
But because it's so primal, it can also be manipulated, which marketers, media personalities, and politicians take advantage of on a daily basis. It's important we recognize the difference between real dangers and false ones in our daily lives.