Dynamic Systems Theory (DST) known popularly as chaos theory, is based under systems theory proposed by russian movement neurophysiologist Nicholai Bernstein, and many other theoretical approachs. DST principal researcher is Esther Thelen, from Indiana University/USA. Thelen applied DST concepts to the study of infant motor development and cognition. Thelen's seminal work was infant stepping reflex. Through this research she could explain that new patters of behavior are not preprogrammed, gene coded nor only controlled by brain, but many other factors are at the same level of importance as the brain. Thelen doesn't see motor development as a separate process, but as a process of problem-solving in which she agregated to DST concepts of the ecological psychology (EP). EP points that knowledge comes from the interaction with the environment. Human beings acquire knowledge from the informations of the features of environment, and according to their potentialities at that time, decide of not to act. For more about DST, please let's argue...