Final answer:
Individuals with different levels of neuroticism show varying brain volumes in areas linked to stress and threat response, with high neuroticism associated with an overactive stress response.
Step-by-step explanation:
People who differ in neuroticism show different volumes of areas of the brain that have been implicated in sensitivity to threat and stress. Neuroticism refers to the tendency to experience negative emotions such as anxiety, anger, and sadness. High levels of neuroticism are associated with an overactive sympathetic nervous system and an increased response to stress, which relates to changes in the brain's structure, particularly in regions like the hippocampus that are involved in stress response and emotional regulation. In contrast, people with low levels of neuroticism tend to be more emotionally stable and their brains show different patterns in these regions.