According to the course lecture material, stress affects the body in three categorical ways including cognitive, behavioral, and ___.

emotional

Explanation:

Stress: In psychology, the term "stress" is described as an individual's feeling of physical or emotional tension. Therefore, stress can come from any thought or event that can make an individual feel nervous, frustrated, or angry. Significantly, stress is considered as an individual's bodily reaction towards a specific demand or challenge. However, stress can be "positive" as well, for example, when it helps a person to avoid danger.

Signs: Headaches, problem sleeping, dizziness, etc.

In the question above, the given statement represents the "emotional" component.

because the early people found out about it.