Secrets of Yawning Revealed     Well, pandiculation is the act of yawning and stretching. Have you started yawning yet, or caused your classmates to begin? Because yawning is . Yawning first becomes so between the first and second years of life. But the first time a person ever yawns is around eleven weeks after conception before even being born. And how long does a yawn last? Well, on average, about six seconds.