|Test:||Schizotypal Personality Questionnaire, SPQ|
Total SPQ Score
[ average score ]
Ideas of Reference
Odd Beliefs or Magical Thinking
Unusual Perceptual Experiences
Odd or Eccentric Behavior
No Close Friends
Suspiciousness / Paranoid Ideation
Total score of 41 or more is considered as a risk of schizotypal personality disorder.
In the original population on which the instrument was developed, norms were as follows:
• 26.9 ± 11.0 (sample 1, n=302)
• 26.3 ± 11.4 (sample 2, n=220)
Ten percent high and low cut-offs on the distribution of scores of the SPQ were 41 and 12 respectively.
The population consisted of Californian undergraduates at a large private university in Los Angeles, and experience has shown that they appear to have higher scores than more selected undergraduates (e.g. medical students in England) and other community populations. It is likely that the culture in Los Angeles provides a more comfortable atmosphere for the expression of unusual ideas, odd beliefs, and eccentric behavior than some other locations, resulting in greater representation of high schizotypal scorers in the original sample. Schizotypy scores are also consistently found to be higher in adolescents and young adults (both on the SPQ and other schizotypy scales), and furthermore scores can be influenced significantly by the research context and local sub-culture.
It is recommended therefore that researchers interested in defining extreme groups in their studies should not stick rigidly to the original normals, but should instead develop their own high-low cut-offs based on normative data from their population of interest.