Mind, Body, World- Foundations of Cognitive Science, 2013a

process, resulting from the interactions between the ants marking in both directions.
(Goss et al., 1989, p. 581)
5.3 Stigmergy and Superorganisms
To compute solutions to the travelling salesman problem, ants from a colony interact
with and alter their environment in a fairly minimal way: they deposit a pheromone
trail that can be later detected by other colony members. However, impressive examples
of richer interactions between social insects and their world are easily found.
For example, wasps are social insects that house their colonies in nests of intricate
structure that exhibit, across species, tremendous variability in size, shape, and location
(Downing & Jeanne, 1986). The size of nests ranges from a mere dozen to nearly
a million cells or combs (Theraulaz, Bonabeau, & Deneubourg, 1998). The construction
of some nests requires that specialized labour be coordinated (Jeanne, 1996,
p. 473): “In the complexity and regularity of their nests and the diversity of their construction
techniques, wasps equal or surpass many of the ants and bees.”
More impressive nests are constructed by other kinds of insect colonies, such
as termites, whose vast mounds are built over many years by millions of individual
insects. A typical termite mound has a height of 2 metres, while some as high as 7
metres have been observed (von Frisch, 1974). Termite mounds adopt a variety of
structural innovations to control their internal temperature, including ventilation
shafts or shape and orientation to minimize the effects of sun or rain. Such nests,
seem [to be] evidence of a master plan which controls the activities of the builders
and is based on the requirements of the community. How this can come to pass
within the enormous complex of millions of blind workers is something we do not
know. (von Frisch, 1974, p. 150)
How do colonies of simple insects, such as wasps or termites, coordinate the actions
of individuals to create their impressive, intricate nests? “One of the challenges of
insect sociobiology is to explain how such colony-level behavior emerges from the
individual decisions of members of the colony” (Jeanne, 1996, p. 473).
One theoretical approach to this problem is found in the pioneering work of
entomologist William Morton Wheeler, who argued that biology had to explain how
organisms cope with complex and unstable environments. With respect to social
insects, Wheeler (1911) proposed that a colony of ants, considered as a whole, is actually
an organism, calling the colony-as-organism the superorganism: “The animal
colony is a true organism and not merely the analogue of the person” (p. 310).
Wheeler (1926) agreed that the characteristics of a superorganism must emerge
from the actions of its parts, that is, its individual colony members. However,
Wheeler also argued that higher-order properties could not be reduced to properties
212 Chapter 5