Answer to Question 1
Recent versions of Gray's theory link extraverts' higher levels of positive affect to the BAS. For example, reviewers of the ties between the dopaminergic systems (associated with feeling good) and extraversion conclude that there is a strong connection between the two. A more dominant BAS could account for extraverts' higher well-being scores than introverts since extraverts are more likely to find all positive experiences more rewarding, including positive social experiences. In contrast, as you would expect, some research findings show those with low BAS sensitivity are more prone to depression. So in simple terms, high BAS sensitivity equals more positive affect and low BAS sensitivity equals less positive affect.
Answer to Question 2
The Behavioral Approach System (BAS) motivates us to approach potentially rewarding situations or stimuli whereas the Behavioral Inhibition System (BIS) inhibits action and is associated with avoidance behavior. Thus, persons high in BAS sensitivity show exaggerated positive affect (e.g., happiness) to rewards and persons high in BIS sensitivity show exaggerated negative affect (e.g., anxiety) to aversive stimuli. For example, a daily-event-diary study found that participants with greater BAS sensitivity (as measured by a self-report instrument designed to measure levels of BAS and BIS) record more positive affect throughout their days, yet those with greater BIS sensitivity report more daily negative affect.
