Here you can access a number of questionnaire measures that I have published. They are all free to use for research purposes, but I would ask that you first email me (  to give me a very brief description of your proposed research. I can sometimes help with translations into other languages. Just go to the tabs at the top of this page to access the relevant instrument.

The Schizotypal Personality Questionnaire (SPQ) is a well-used measure of schizotypal personality based on DSM criteria for schizotypal personality disorder. There is an adult version (SPQ) and also a child version (SPQ-C). There is also a brief version for adults (SPQ-B).

The Reactive-Proactive Aggression Questionnaire (RPQ) is also a well-used brief self-report measure for assessing two different forms of aggression – Reactive (hot-blooded, impulsive) and proactive ((cold-blooded, planned). There is an adolescent version, an adult version, and a child version.

The Cognitive, Affective, and Somatic Empathy Scales (CASES) is a 30-item self-report scale to measure three forms of empathy – cognitive, affective and somatic. Each subscale can be divided into two sub-forms of empathy – positive and negative. The scale was designed to be used with both adults and children.

The Selfishness Scale (SQ) is the first self-report scale to assess selfishness. In addition to a total score, this brief 24-item scale provides measures of three forms of selfishness – egocentric, adaptive,  and pathological. It can be used with both children and adults.

The Conduct and Oppositional Defiant Disorder Scales (CODDS) is a five-minute 26-item self-report measure of DSM 5 conduct disorder and oppositional defiant disorder in both children and adults. Parent can also report on their children. It comes with a 12-item self-report Limited Prosocial Emotions scale (LPE) which measures the four dimensions of LPE as outlined in DSM 5 in both children and adults. Parents can also report on their children.