// The Song Remains The Same

(This is part 2 of a continuing series entitled “The Principles of Self Organization”; The first article was entitled “Emergence“)

Feedback is a driving mechanic in the process of self organization. There are two types of feedback, positive and negative; positive feedback generally promotes change in a system, where negative feedback controls change in a system. In effect, these two mechanisms are complimentary and work well together in highly dynamic systems.

A good example of this effect in nature is decentralized clustering in termite colonies. In social insect colonies such as termites, each agent or insect performs many types of tasks on their own without any direct instruction from a leader or manager termite. One of these processes is pebble clustering which is used in chamber formation in termite nests. These complex chambers are constructed entirely by decentralized agents only reacting to local stimuli and their own internal state. One such process involved in building termite nests is pebble clustering. A termite’s attraction towards large piles of pebbles biases it towards adding to large piles, which is positive feedback. Large piles tend to have more pheromone which attracts more termites that in turn potentially drop more pebbles on the pile. Over time, many pile centers form, and geometric patterns emerge in the nest, all through individual efforts collaborated via decentralized indirect coordination.

Positive Feedback is a technique used to create and amplify patterns. Without positive feedback, a static system will remain static with no change for new pattern creation. However, with too much positive feedback, the amplification effect will dominate and the system will be overloaded with chaos. The amplifying effect of positive feedback takes an initial change in a system and reinforces that change in the same vector as the original deviation. One such example of this is the explosive growth of human population in developing regions of the world. Positive feedback amplifies fluctuations in populations in interacting subunits. The amplifying nature of positive feedback means that it has the potential to create change in a system as well as destructive explosions or implosions in any process where it is employed. This spot between a static system and complete anarchy is sometimes referred to as “The Edge of Chaos”.

The start of pattern creation is a basis for the underlying mechanics of social insects, biology, and nature itself; However without a control mechansim, without something to slow down or stop the amplification of positive feedback, these processes could not exist. This is where negative feedback comes into play, which is the next article in my series on the principles of self organization.