Objective: This master thesis aimed to study neuropsychological functioning and psychopathic traits among delinquent adolescents within a Juvenile Justice Institution (JJI) in the Netherlands. The research question ‘In what way is neuropsychological functioning related to psychopathic traits among delinquent adolescents?’ was explored through three hypotheses; delinquent adolescents with higher Verbal IQ and Verbal Comprehension Index scores show more traits of the interpersonal domain (1), delinquent adolescents with better performance on sustained attention show more traits of the affective domain (2), and delinquent adolescents with lower inhibition scores show more traits of the behavioural domain (3).
Method: Fifteen adolescents were tested for IQ (WISC-III, WAIS), sustained attention (BourdonVos), impulsivity/inhibition (Stroop) within the JJI. The Youth Psychopathic trait Inventory (YPI) was used to assess psychopathic traits. Performance on the neuropsychological tests was compared with the interpersonal domain, affective domain and the behavioural domain (YPI). Regression analyses were used to investigate whether the significant correlations predicted variance in psychopathic traits.
Results: Among other significant correlations between IQ scores and psychopathic traits that were found, a significant positive correlation was found between Verbal Comprehension and Dishonest Charm (interpersonal domain YPI). Verbal Comprehension did not predict variance in Dishonest Charm. No relationships were found between sustained attention, inhibition/impulsivity and psychopathic traits.
Discussion: Little research had been done on the relationship between psychopathic traits and neuropsychological functioning, but some of the findings in this study were in line with prior research. Most studies were done in the general population and this study is the first in the Netherlands to include detained adolescents. Main limitations were the small group size and the refusal of some adolescents to cooperate, which could result in a bias. Future recommendation is to conduct a longitudinal study which includes normal controls, focussing upon the relationship between IQ, psychopathic traits and the severity of the crime committed. The results of this study can be taken into consideration when diagnosing delinquent adolescents and when starting treatment.