6. “Fixed Action Pattern” May Explain Contagious Yawning
Fixed action pattern generally refers to instinctual behavior that has to occur, to the point of completion, as a biological necessity. Fixed action pattern is quite common in the animal kingdom but can also occur among humans. It is caused by specific neural networks that are responsive to external stimuli, such as seeing another person yawning.
When the external stimulus reaches the neural networks, a release pattern begins, in which the person (or animal) has to complete an action in an instinctual response. Some scientists think that when you watch someone yawn, the fixed action pattern kicks in, causing other people to yawn in response.