Answer to Question 1
Answer: Introverts prefer the company of family and friends to large gatherings of people, but they are not hermits who isolate themselves. In contrast, the extravert seeks stimulation and excitement. Extraverts are more sensitive to rewards and prone to experience more positive feelings when they have a chance to earn rewards. Extraversion is linked with better mental health, and extraverts are less likely than introverts to experience mood or anxiety disorders.
Answer to Question 2
Answer: Labels and descriptors can be useful but they leave out a lot of important information. Most people do not score at the extreme ends on any trait. That is why each person's trait is scored on a continuum from low to high. Being extraverted means scoring higher on a dimension ranging from introversion to extraversion than someone who scores lower on that same dimension.
Retrograde pyelography (RP). Note the contrasting of the renal calyces, ureters, and bladder followi
Enhancement of Contrast
Neural Basis of Enhancement of Contrast
How lateral inhibition produces contrast enhancement. (Based on Ratliff, 1972.)
Bar-eye phenotypes in contrast to the wild-type eye in Drosophila