Why do we follow suit when we see others yawning?

We yawn when we are tired or sleepy. Physiologically speaking, yawning is a response to fatigue or lack of stimulation. It is an involuntary reflex that is said to be triggered when blood needs more oxygen. However, this may not be the case always. We often find ourselves yawning in response to another person doing so. A study was carried out to find out why exactly that is. The findings of that research show that this chain reaction effect of yawning may be related to what is known as social mirroring. 

Social Mirroring 
It is a phenomenon where one person unconsciously imitates the gesture, speech pattern, or attitude of another. This can be seen in case of other physical behaviours as well like scratching the face, crossing the legs, etc. 

The mirror neurons in the brain are activated to feel a stronger connection with another individual. It is distinct from simple imitation as most of the time, the person who is mirroring the movement of another isn’t even consciously aware that he is doing so. Mirroring establishes a sense of connection between two individuals as the similarities in non-verbal gestures lead to a belief that they must have similar attitudes and ideas as well. 

The mirroring effect being triggered by yawning is seen as a god sign as it signifies empathy and bonding between different individuals. While studies have shown that the amount of empathy a person has is usually directly proportional to how likely they are to yawn after seeing someone else do. However, these results shouldn’t be generalised as an indicator of psychopathic or sociopathic tendencies. Lack of contagious yawning is often seen in people who present with autism spectrum disorder or schizophrenia. 

Some studies speculate that people may generally become less susceptible to contagious yawning as they age, possibly because they pay less attention to the behaviour in others. 

Is social mirroring observed in other species? 
This spontaneous response is not something unique to humans. Some species of primates and canines yawn in response to each others’ yawns, and dogs will even yawn after a person yawns. This prompts a theory that contagious yawning is a primitive form of unconscious communication and bonding that helped our ancestors stay safe and avoid danger long ago. This behaviour, the researchers think, might serve as a warning sign to others of potential threats.