Psychopathy is regarded as a dimensional concept - i.e., a person can be more or less psyhopathic. This approach enables psychopathy to be measured with reliable, validated personality scales, and to be related to impairment of serontonergic function in the brain. Several personality inventories are described in the article, especially the Karolinska Scales of Personality, the Zuckerman Sensation Seeking Scales, form V, the Eysenck Personality Questionnaire, including an impulsiveness scale from the IVE (Impulsiveness-Venturesomeness-Empathy) inventory, and the old dimensional scale, the Marke-Nyman Personality Temperament scale based on the personality theory of Henrik Sjöbring. In this way both old and new, and both Swedish and foreign personality concepts are linked together. Personality scales are easy to use and enable better stability and validity of results to be attained.

Genom att välja personlighetsinventorier för att undersöka såväl friska som personlighetsstörda personer kan personligheten länkas till dysfunktionen i det serotonerga systemet. Därigenom kan vi få möjlighet att erhålla en större samstämnighet och tillförlitlighet i rättspsykiatriskt undersökningsarbete. Bristande överensstämmelse mellan olika rättspsykiatriska bedömare är ett uppmärksammat problem.