The relationship between Gray's and Eysenck's personality spaces

In a sample of 171 healthy volunteers, the present study examined the relationships between questionnaire measures of trait anxiety, punishment sensitivity, and impulsivity with the measures from the Eysenck Personality Questionnaire (EPQ). This was undertaken in order to explore the relative location of the personality dimensions central to the ideas of Gray and Eysenck. Results confirmed that the behavioural inhibition personality dimension (anxiety) lies at a non-negligible angle relative to neuroticism (N) especially when measured via special purpose questionnaires. This dimension also appeared largely independent of psychoticism (P) which suggests limits on the importance of a hypoactive behavioural inhibition system in psychopathy. The behavioural activation personality dimension (impulsivity) may not be orthogonal to the inhibition/anxiety dimension as it related to P in addition to N and EPQ-extraversion. The relationship of impulsivity to EPQ measures was a function of sex, however; thus, experiments relating personality questionnaires to the behaviours specific to the behavioural activation and inhibition systems may prove more reliable when sex is routinely included as a factor