Agreeableness, conscientiousness, and psychoticism: distinctive influences of three personality dimensions in adolescence

Researchers have suggested that the psychoticism (P) personality dimension of the Eysenck Personality Questionnaire may be largely redundant with the agreeableness (A) and conscientiousness (C) constructs of the five-factor model. Little research has examined the distinctiveness of these constructs. We utilized a multi-wave, multi-method design to examine the ability of C, A, and P to uniquely predict a number of important outcomes amongst high school students. A total of 778 students (391 males, 387 females; mean age 15.41 years.) completed personality measures in Grade 10. Self-reported self-esteem, social support, health-related behaviours, religious values as well as teachers' assessments of students, were collected 1 and 2 years later. A, C, and P were distinctive in their ability to predict these outcomes, after controlling for gender and socio-economic status as well as Grade 10 extraversion, openness, and neuroticism. The individual P items explained unique variance over and above that explained by A and C. It was concluded that P is not merely the opposite of A and C. Implications for interventions are raised.