Why do people yawn when they see other people yawning?

People often yawn when they see others yawn due to a phenomenon called contagious yawning, which is thought to be linked to social bonding and empathy. This involuntary response may signal a shared state of alertness or relaxation within a group. Research suggests that it may be more common among individuals who have strong social connections, reflecting an instinctive way to synchronize behavior and emotions.