Final answer:
Inability is the least prevalent symptom of stress among Americans, in contrast to more common symptoms like headaches and fatigue. It refers to extreme reactions like severe crises or death due to minor stressors.
Step-by-step explanation:
The least prevalent physical symptom of stress among Americans seems to be inability, which in this context likely refers to an extreme outcome such as the inability to cope with minor stresses leading to significant crises or death. This is a less common manifestation when compared to more frequently reported stress symptoms like headache, fatigue, and anger. In the literature, stress is shown to evoke various physiological, cognitive, and behavioral responses. It is not just the momentary 'fight or flight' response, but when enduring stress in the long term, symptoms such as profound fatigue, depression, and severe immune system suppression can occur, indicating the severity of stress an individual is experiencing.