The development of the Gray-Wilson Personality Questionnaire is described; this is an instrument designed to measure human equivalents of six animal behaviour paradigms--Approach, Active Avoidance, Passive Avoidance, Extinction, Fight and Flight. Although these six scales showed satisfactory internal consistency they failed to link up into the three major systems suggested by Gray's personality theory. The strongest associations were between Fight and Approach and between Flight and Passive Avoidance. This raises questions as to how the neurological systems of activation, inhibition and fight/flight are related to human personality structure.