Electroencephalographic (EEG) activity was obtained under eyes open and eyes closed conditions from ten families, each consisting of a biologically related father, mother and two children. Spectral power (microV2) and mean frequency (Hz) measures from the delta, theta, alpha-1, alpha-2, beta-1, and beta-2 bands were computed for each family member. Non-family controls were constructed from the real family data by randomly pairing non-related individuals with one another, and correlations between the analogous individuals were also computed. The correlations for spectral power between family groups were greater than those obtained from the non-families for theta, alpha, and beta band power. The correlations for mean frequency between family members were greater than those of the non-families for the delta, theta, and alpha bands, although these were not as robust as the spectral power findings. In general, few family membership effects were found for the eyes open/closed or electrode site conditions. The results support findings from twin studies that suggest EEG characteristics are determined at least in part by genetic factors.