Chapter 4: Stress Management and Sleep 73 Stress Theories Research has shown a strong correlation between stress, performance and health (Selye, 1974). How the stress is perceived and the body’s response can either positively or negatively impact performance. There are several theories that attempt to describe or define the relationship between stress and performance. Drive Theory. The drive theory was one of the first theories to be developed and suggested a linear relationship between arousal (stress) and performance. It theorized that any stress, whether eustress or distress, would have a positive impact on performance. In essence, the greater the stress, the greater the performance (Hill, 1957). The drive theory is illustrated in Figure 4.1. Figure 4.1. Relationship Between Stress and Performance According to the Drive Theory Inverted-U Theory. Contrary to the drive theory, other studies suggest that the relationship between stress and performance is not always linear (Yerkes & Dodson, 1908). Additionally, although stress does enhance performance, it does so only to a certain level. In essence, there is a point where continual increases in stress start to decrease performance rather than increase it. Researchers referred to this phenomenon as the inverted- U theory of stress. As demonstrated in Figure 4.2, low to moderate levels of stress enhance performance, whereas, extremely high levels decrease it.