15. Yawning May Be Connected To Our Biological Clocks
Our biological clocks are internal mechanisms that regulate our activities in keeping with our physical needs. For example, our biological clocks tell us when we need to go to sleep, often at the same time each day.
Some scientists believe that yawning may be an evolutionary trait that is connected to our biological clocks. It may be an impulsive behavior in which our ancestors’ bodies signaled that they need to switch to a different activity. The act of yawning rebooted their brains so that they could effectively end one task and begin a new one.