Part one of term paper
Studies on the physical and wning The act of yawning has been observed in all vertebrates, and occurs in humans as early as minutes after birth, so it must have some definitive physiological purpose. Until recently, most scientists believed yawning was a respiratory function, triggered by a surplus of carbon dioxide in the bloodstream. In t ...

Part two of term paper
... research had drawn loose ties between arousal and yawning; for example, one study showed that yawning in rats increased with the presence of a penile erection. To show that arousal increases with the onset of a yawn, the authors of this study designed a correlational experiment to measure changes in physical indicators of arousal before, during, and after yawning. They predicted that signs of arousal would increase when the yawn started. A mixed-gender group of 30 college students participated in ...