The amygdalae of introverts and extroverts responded with equal activity to negative facial expressions. Happier faces, however, show strong responses only in those people rated as extroverts.

• 性格内向者和外向者的扁桃体对消极的面部表情有相同的反应。然而，较快乐的脸只在那些被认为性格外向的受测者身上有很强的反应。