Two aspects of genetic-invironmental interaction in human development-specific and individual-are analysed. The former is connected to ontogenetic realization of normative laws determining universal for human population traits. Possible mechanisms of genotypic influence on psychic development are considered. Normative laws of genetic-environment interaction and genetic-environmental interaction in individual psychological traits' formation are independent phenomena. The latter can be experimentally studied by special genetic methods. The possibilities of these methods usage in psychological research (for instance, in the study of developmental stages order and of the role played by environmental factors in individual differences' formation) are analysed.