Twins and family study enables to conclude that individual aggression differences are considerably (almost 50 %) caused by genetic factors. The allfamily environment is not a significant determinant in adults aggression, while the individual one, on the contrary, accounts for no less than a half of its dispersion. At the same time the increased aggression in people with different chromosome anomalies is in most cases a part of a general desadaptation syndrome considerably made up with psychological factors namely. Information concerning molecular-genetic aggression pre-requisites is meanwhile incomplete and in some cases contradictory which is mostly accounted for by the sexual or age factors impact as well as by the fact that molecular-genetic aggression prerequisites are apparently unlike different diseases.