Just as with descriptions of stability, it may seem that the search for explanations for stability would be a waste of developmentalists’ time. And indeed, if researchers assume that the natural state of all phenomena is constancy or continuity, that is, if they assume that all phenomena are inherently at rest, then no explanations for this state are needed. However, if, on the other hand, change is assumed, then the natural state of all phenomena is considered to be movement or flux, and explanations are needed for how constancy could be accomplished. In general, such states of stability or constancy are often described as “steady states,” and they are considered to be achieved through active means, such as are visible in all those activities needed to maintain the steady state of “balance” when walking on a narrow ledge or, over longer periods of time, all those activities needed to maintain a constant weight. These active processes are captured in concepts such as maintenance, conservation, preservation, compensation, equilibrium, homeostasis, or homeorhesis.