Under arousal theory, performance tapers off during underarousal and:

1. The relationship between arousal and performance is an inverted curve. 2. Performance is maximized at the optimal level of arousal. 3. It tapers off during under- and overarousal. 4. So both too little and too much arousal hurt performance. _Source: OpenStax Psychology 2e (CC BY 4.0), Ch 10 'Emotion and Motivation', sections 10.1-10.4_