This book presents current research in the field of psychology, with a particular focus on the classifications, influences and effects of personality. Topics discussed include the contribution of personality to positive psychology; narcissistic and borderline personality traits; personality traits and daily moods; schizotypal personality traits; the imaginary companion experience in adults; structural and functional neuroimaging of the anxiety-related personality trait; child and adolescent personality development and assessment and a psycho-social approach to meanings and functions of trait labels.