Students were given a firsthand experience of their "Fight or Flight" Responses in action. After giving two warnings about cell phones in class, the teacher smashes a student's "cell phone" after he leaves it on his desk. Based on their faces and body language, you can see a variety of reactions while the students try to process the situation. The student is in on the joke and the "cell phone" is actually the teacher's dead calculator with a broken screen. The calculator was planted at the start of the class period.