No you can't. What is commonly called being a psychopath/sociopath is professionally termed antisocial personality disorder. One of the most significant features of this disorder is not only complete lack of empathy but taking pleasure in inflicting pain and suffering and blaming of victims. Like all personality disorders, antisocial PD can only be diagnosed in adults since children and adolescents haven't fully developed their personality. Normal child and adolescent development includes egocentrism so it would be impossible to conclude that even mentally ill child or teen will necessarily carry disordered behavior into adulthood. Certainly there could be predictors of adult antisocial personality disorder but nothing definitive (which is essentially what the article was getting at). There are two potentially severe behavior disorders that occur in children and can make them act like holy terrors, conduct disorder and oppositional defiant disorder (the distinguishing featuring being the target of aggression, the former involving general targets and the latter only authority figures). There is a much higher concordance rate for antisocial PD and conduct disorder than with oppositional defiant disorder and the current DSM criteria require that an individual have displayed evidence of conduct disorder before age 15 to be considered for antisocial personality disorder as an adult. However, only 25-40% of children with conduct disorder with have antisocial personality disorder as an adult (i.e. - become a psychopath). Certainly children, like some mentioned in the article, can show antisocial traits during childhood. Nonetheless, it would be impossible to presume adult personality in a still developing child, no matter how volatile. Especially considering most children outgrow the deviant behavior and only a minority become adult psychopaths.