The drawbridge effect means that when a person crosses the drawbridge in fear, his heart will beat faster involuntarily. If he happens to meet another person at this time, he will mistakenly think that the heartbeat caused by this situation is the physiological reaction that the other person makes him move, so he breeds love for the other person.

When people live in a dangerous situation, they will involuntarily experience the phenomenon of rapid heartbeat and shortness of breath, and form corresponding fears, which are independent of people's will. Those who are on the dangerous bridge are more likely to be physically excited.