As we have seen, nonlinearity and complexity can lead not only to greater unpredictability in a system, paradoxically, they can also yield predictable behaviors. One reason for this strange blend is the way components and subsystems of complex systems become coupled with one another in feedback types of relationships. Sometimes this coupling leads to the kind of nonlinear amplification seen, e.g., in chaotic systems, and other times nonlinear coupling can produce phases of more stability, and hence, greater predictability. Therefore, planners as cartographers of the complex world need to be familiar with various kinds of regions of nonlinear predictability.

Consider, for example, the curious behavior that takes place when pendulum-driven clocks are hung on a wall already containing similar clocks: the new clocks become in-phase with the clocks already hanging there, i.e., the periodic swings of the pendulums lock-into the same frequency. As a result, before a clock is hung on the wall, if the phase of the clocks already hung is known, then one can predict the eventual phase of the new clock Ñ it will be the same as the clocks already hanging. This phenomena of frequency-locking called "entrainment" is one of the strange features of complex systems.

A similar frequency-locking phenomenon can be seen in the case of large- scale weather patterns such as the now notorious El Nino, the seemingly erratic warming of the equatorial surface waters extending west into the Pacific Ocean off the coast of South America, a phenomenon now known to deleteriously effect global weather patterns. This year El Nino has been blamed for Hurricane Linda, the most powerful Eastern Pacific Hurricane on record. The name "El Nino" comes from the Spanish for "the Christ Child" because this weather pattern has tended to occur around Christmas time.

El Nino is a very nonlinear complex system due to the pervasive feedback loops between oceanic phenomena (e.g., water temperature both on the surface as well as deeper as well as current speeds and extension) interacting with atmospheric phenomena (e.g., air circulation and temperatures) ( Jin, F.F., Neelin, J.D., & Ghil, M., 1994; and, Tziperman, Stone, Cane, & Jarosh, 1994). The nonlinearity of El Nino is even heightened when the seasonal cycle is added to the picture (See Appendix B). Yet, instead of this additional nonlinearity making the system more unpredictable, it can, under some conditions, actually serve to make El Nino more predictable through engendering both a new kind of stability in the system, i.e., the way the El Nino cycle can become entrained (like the pendulum-clocks above) with the seasonal cycle, as well as putting the mathematics of the El Nino nonlinearity within the known dynamics of the so- called routes to chaos. The type of emergent stability of entertainment or frequency-locking can lead to greater predictability since the system can be temporarily "stuck" at these particular phases. Through the on-going intensified exploration of such nonlinear phenomena, the predictability of complex systems will only increase. Again this is an area of nonlinear dynamics which leader/planners will need to know how to get around in.