The hypothesis that personality is more differentiated, or variable, for individuals higher in intelligence was tested in a large sample (N = 1,050) of young Croatian adults. Participants completed a measure of the Big Five personality factors in self-report format. Also administered was a verbal ability test as an estimate of intelligence. As the verbal ability scores had a normal distribution, tertile splits were created and the lower group's means, standard deviations, scale ranges, and the coefficient alpha for each scale. The higher ability tertile had higher internal consistency estimates, greater scale variances, and slightly larger scale ranges. The results therefore provide some support for the differentiation of personality by intelligence hypothesis and do suggest that personality scale responses may differ depending on the intelligence level of the sample.