How valid is the psychoticism scale? A comment on the Van Kampen critique


  • Hans J. Eysenck

    Corresponding author
    1. Institute of Psychiatry. London, UK
    • Department of Psychology, Institute of Psychiatry, De Crespigny Park, Denmark Hill, London SE5 8AF, UK
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Van Kampen (1993) has published a paper in which he criticizes the concept of psychoticism and the use of the P scale as a measuring device, and advances measures for his own S scale and its validity. This reply attempts to clarify the notion of ‘validity’, and to demonstrate that there is a considerable body of experimental evidence to show that P has a high degree of construct validity, whereas the Van Kampen S scale lacks completely any degree of construct validity. Several examples are given of how the experimental evidence legitimates both the P scale, and the theory (nomological network) on which it is based.