In the paper the data obtained in the laboratory in the course of the long-term studies are reviewed. The results allowed to establish that the dominanta principle is not only the basis of the nervous system activity but also a regulator of the motor activity of a developing organism at all stages beginning from the zygote, i.e. before the maturation of the nervous system. Attention is paid to the role of the dominanta principle in a realization of the "energetic rule of the skeletal muscles" and hence to its significance as a main factor determining the individual development of the organism.