A personality test developed in Lleida and in the United States is capable of measuring personality disorders by unifying the criteria of the World Health Organization and the American Psychiatric Association

For the first time, the test unifies the two classification systems of maladjusted personality or personality disorders of the two organisations

Researchers from the University of Lleida (UdL) and the Biomedical Research Institute of Lleida (IRBLleida) and the University of Delaware (the United States) have developed a model for the study of human personality that unifies, for the first time, the two classification systems of personality disorders, that of the World Health Organization (WHO) and that of the American Psychiatric Association (APA). The study, which has been published in the journal Personality Disorders: Theory, Research, and Treatment, has been led in Lleida by Anton Aluja, professor of Personality and Psychopathology at the UdL and principal investigator of the IRBLleida research group Neurocognició, Psicobiología de la Personalidad y Genética de la Conducta.

"The advantage of this model is that it is capable of unifying the two WHO and APA classification systems of personality disorders, which have some differences, and therefore this five-factor model that we propose may be useful for better understanding the position of pathological or maladaptive personality traits" explained Aluja. The Zuckerman-Kuhlman-Aluja Personality Questionnaire (ZKA-PQ) is the name of the test that postulates that the human personality has a strong biological basis, independent of the individual's culture, and is stable throughout life. The model considers twenty facets of personality, grouped under five factors: aggressiveness (physical aggression, verbal aggression, anger and hostility), activity (compulsion to work, general activity, restlessness, and energy at work), extraversion (positive emotions, social warmth, protagonism and sociability), neuroticism (anxiety, depression, dependence and low self-esteem) and sensation research (emotion and adventure research, experience research, disinhibition and sensitivity to boredom/impulsiveness).

Research staff from the University of Almeria, the Autonomous University of Madrid, the Hospital Clinic of Barcelona and the Augusto Pi y Sunyer Biomedical Research Institute (IDIBAPS) have also participated in the research. The study analysed the responses of 1,229 people aged between 18 and 80 from Lleida and Madrid, who completed the pot.


Aluja, Anton & Sayans-Jiménez, Pablo & Garcia, Luis & Gutiérrez, Fernando. (2020). Location of International Classification of Diseases-11th Revision and Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, Dimensional Trait Models in the Alternative Five-Factor Personality Space. Personality Disorders: Theory, Research, and Treatment. 10.1037/per0000460.

IRBLleida belongs to the Institution of Research Centres in Catalonia (iCERCA), which is organised according to a model of good governance and operation that ensures the efficiency, management flexibility, attraction and promotion of talent, strategic planning and executive capacity of the research centres in Catalonia.

The study was led in Lleida by Anton Aluja, Professor of Personality and Psychopathology at the UdL and principal researcher