Ants, Not Autocrats

Ants , Not Autocrats

Hierarchical and centralized control is anathema in the object paradigm. It is replaced with a kind of blind coordination, as exemplified in the traffic signal example in Chapter 3, From Philosophy to Culture. A traffic signal is blind in the sense that it does not need any awareness of other objects or their goals to accomplish its own tasks . Any sense of traffic control has been distributed to the collection of objects in the intersection and not to any single object.

The traffic signal assumes responsibility for monitoring the passage of time and cycling through a change of states at appropriate intervals (green for 20 seconds, yellow for 10 seconds, red for 30 minutes). ^[2] It also assumes responsibility for notifying others of its current state by broadcasting that state via an externally observable colored light. Automobile (or driver) objects assume responsibility for inhibiting or expressing their own behavior (stop on red, go on green, accelerate on yellow) ^[3] as a consequence of their awareness of the signal. Neither automobiles nor drivers know anything about the workings of traffic signals, just as signals know nothing about automobiles or drivers.

This kind of blind coordination seems to work well in small-scale examples such as the traffic signal, but does it scale up? The answer, suggested by ants, termites, and biological communities, is yes. Hive communities collectively construct extremely elaborate structures and efficiently exploit natural resources (such as food) without the need for architects or overseers. No single ant is in charge of making sure that a group of ants perform. Food foraging begins when a single discoverer ant broadcasts the discovery of food to the other ants by exuding a particular pheromone. Other ants detect the pheromone and respond by moving to the food source and then back to the hive, also exuding the same pheromone. No ant is aware of the identity of any  other ant. They do not seem to care whether other ants are around. They simply detect an event (receive a message) and respond according to their intrinsic nature.

The attempt to establish centralized economies and management in the precollapse Soviet Union is a contrasting example of autocratic top-down control. It suggests that although it might be possible to construct very small-scale, control-oriented systems, it does not work on a large scale. The emerging discipline of complexity theory also provides insights into the limitations of control in large systems.

Note  

If the idea of patterning software architectures on ant or termite colonies makes you uneasy, you might consider the work of Marvin Minsky (a significant contributor to OO programming as well as to AI theory) and the work of Murray Gell-Mann, Stuart Kaufmann, and many others at the Santa Fe Institute. In his Society of Mind book, Minsky posits the construction of intelligence by utilizing nonintelligent actor/ agents (objects) that make simple decisions based on their own local awareness of themselves and their individual circumstances. These simple agents are aggregated in various ways until they form a society of mind, which is also the title of the book in which these ideas are formulated. Gell-Mann and Kaufmann are among the founders of the Santa Fe Institute, the center for the study of complex adaptive systems. Complex systems are characterized by simple elements, acting on local knowledge with local rules, giving rise to complicated patterned behavior. And of course, you should consider the fact that XP asserts that large systems can, do, and will emerge from the creation and implementation of small local systems.

Note  

In human systems, the presence of strong central control has a debilitating effect. Humans lose their capability of independent action and become dependent on the presence of the controller. If that controller is removed ”as it was in the former Soviet Union ”it can take a long time for the controlled to regain their ability to function autonomously and cooperatively. Software objects designed to function in response to a master controller cannot function in the absence of that controller. This is the antithesis of design based on object thinking.

These two counterexamples provide the basis for the metaphor that objects are coordinated as if they were ants and that no object attempts to assume the role of autocrat controlling the behavior of other objects.

^[2] OK, only subjectively.

^[3] Observed but highly improper behavior.