Psychologists define the 'dark core of personality'. All dark personality traits can be traced back to the general tendency of placing one's own goals and interests over those of others even to the extent of taking pleasure in hurting other's

See the source article by following the link below:
Psychologists define the 'dark core of personality'. All dark personality traits can be traced back to the general tendency of placing one's own goals and interests over those of others even to the extent of taking pleasure in hurting other's