what causes yawning and what is it
While many take yawning to be a sign of tiredness, sleepiness, stress or simply a lack of interest, it could even be an indicator of many other physiological phenomena. This write-up elucidates on what causes one to yawn. Advertisement.hile many take yawning to be a sign of tiredness, sleepiness, stress or simply a lack of interest, it could even be an indicator of many other physiological phenomena. This write-up elucidates on what causes one to yawn. Advertisement.