How personality relates to intelligence test performance: Implications for a theory of intelligence,ageing research and personality assessment

Previously reported findings indicate that variation of EEG evoked potential parameters is strongly related to both personality and intelligence differences (Robinson, 1982a, b). These data and the associated theory imply that personality should relate to intelligence test performance. Results are described in this report which indicate that subtest profiles obtained with the Wechsler Adult Intelligence Scale (WAIS) differ significantly for Ss scoring highest and lowest on the Extraversion (E) scale of the Eysenck Personality Questionnaire (EPQ); introverts tend to do better on the ‘Verbal’ subtests while extraverts tend to do better on the ‘Performance’ measures. Ss with middling scores on the E scale of the EPQ can also be distinguished in terms of specific WAIS profiles. In this case the results define two contrasting groups. Young male Ss with middling E scores tend to have high Psychoticism (P) and low Lie (L) scores on the EPQ as well as having distinctive WAIS profiles characterized by higher scores on subtests normally associated with a ‘Memory’ or ‘Attention-Concentration’ factor. Higher scores were also obtained by this subgroup on the Picture Arrangement and Block Design subtests which were previously shown to load a P + /L ? factor. The converse is true for older female Ss who also have middling E scores. As well as demonstrating a systematic relationship between personality and intelligence test performance these data provide some further support for a model of brain-behaviour relationships proposed by Robinson. Within this theoretical framework a neurophysiologically meaningful explanation can be provided for the three major factors that reliably emerge in factor-analytic studies of the WAIS. From an applied viewpoint, the data indicate that personality differences can be assessed from performance on tests such as the WAIS. On this issue the results are discussed with particular reference to Gittinger's Personality Assessment System. Implications for ageing research are also discussed.