PATHOLOGY

Detailed explanation-1: -Taken together, experts believe that contagious yawning may be a social communication tool specific to higher-order animals. In the context of the brain-cooling theory of yawning, perhaps yawning evolved to become contagious as a means to increase the cognitive performance and vigilance of people within a group.

Detailed explanation-2: -Physical Causes-Fatigue, general tiredness, body temperature malfunctions, and stimulation of the vagus nerve can cause frequent yawning. Excessive yawning and sleep disorders are often correlated. Emotional Causes-Anxiety and depression can lead to yawning excessively.