Little is known about high-IQ criminals because they are statistically rare. Only 2 percent of the general population has an IQ score of over 130 and only one in two thousand possesses an IQ of over 150. Another reason little is known is that few are caught. The differential detection hypothesis suggests that people with high IQs are less likely to be detected, arrested, prosecuted, convicted, and incarcerated than others. Prison studies, therefore, are of limited utility, and to study elite crime, self-report is essential. There is, however, little advantage for high-IQ individuals to participate in self-report research—and potentially much to lose. High-IQ individuals often possess the means to block research inquiries. This chapter describes the methodology of the study, including ethical and legal challenges associated with adult self-report research. It describes the study’s sampling, the design of the self-report questionnaire, the rationale and logistics of the follow-up interviews, and the structure of the Eysenck Personality Questionnaire (EPQ-R).
Three Versions of the Perceived Stress Scale: Psychometric Evaluation in a Nationally Representative Sample of Chinese Adults during the COVID-19 Pandemic
