Comparisons between EEG spectral power in the fast alpha (9-12 Hz) range and scores obtained on the Millon Clinical Personality Inventory (MCMI) were made in two populations of subjects. The first was a group of 60 individuals who reported no personal or family history of alcoholism. The second was a subgroup of 13 sons of alcoholics and 13 matched control subjects. In the first population, 30% of the subjects were classified as "high" alpha based on the criteria that their EEG in the 9-12 Hz range was over 75 microV2/octave in amplitude. Using this same criteria, 69% of the sons of alcoholics and 31% of their matched controls were also classified as "high" alpha. In both populations, subjects with high amplitude fast frequency EEG alpha activity in lead P4-O2 scored significantly higher on the Histrionic-Gregarious scale of the MCMI than subjects with low amplitude activity in this lead. These results are consistent with some previous studies showing a positive relationship between EEG alpha activity and extroverted personality traits. These results suggest that fast frequency alpha activity may be associated with some definable personality traits.