Yawning is treated as an impolite action which expresses Boredom. Which is why many hide their Yawning with hands.
Yes it is impolite action. I remember one of my friend got punished in school as he was yawning during a lecture.
If your friend yawned during a lecture, it sends a message to the lecturer that his lecture was boring. Certainly yawning indicates an impolite and uncivilized act.
[{"id":20639,"title":"IPhone","votes":31,"type":"x","order":0,"pct":31,"resources":[]},{"id":20640,"title":"Blackberry","votes":17,"type":"x","order":0,"pct":17,"resources":[]},{"id":20641,"title":"Nokia E Series","votes":21,"type":"x","order":0,"pct":21,"resources":[]},{"id":20642,"title":"Sony Ericsson","votes":13,"type":"x","order":0,"pct":13,"resources":[]},{"id":20643,"title":"China Mobile","votes":3,"type":"x","order":0,"pct":3,"resources":[]},{"id":20644,"title":"Other","votes":15,"type":"x","order":0,"pct":15,"resources":[]}]["#ff5b00","#4ac0f2","#b80028","#eef66c","#60bb22","#b96a9a","#62c2cc"]["rgba(255,91,0,0.7)","rgba(74,192,242,0.7)","rgba(184,0,40,0.7)","rgba(238,246,108,0.7)","rgba(96,187,34,0.7)","rgba(185,106,154,0.7)","rgba(98,194,204,0.7)"]350
