Brain Imaging Studies Conducted by Johnson and Colleagues (1999) Show

Brain imaging studies conducted by Johnson and colleagues (1999) show that introverts are higher in arousability, the degree to which stimulation typically produces arousal of the central nervous system, than extroverts. This study has been used to argue that ______.

A) there may be individual differences in the need for affiliation
B) that introverts may steer clear of social interaction to prevent their arousal level from reaching uncomfortable levels
C) that extroverts may seek out affiliations to raise their level of arousal
D) all of these