Meera Modi, Pursuer of Wisdom
Originally published September 2007.
Ants can accomplish a number of incredible events. They can build structures several million times their own size, they can conquer and enslave competing ant colonies and even bridge cavernous spaces, making chains of their own bodies. But can we really compare the HUMAN BRAIN to a colony of animals with an exoskeleton (never mind their lack of opposable thumbs)? Can “swarm intelligence” rival our own intelligence?
The remarkable nature of “swarm intelligence” is the fact that it is accomplished in the absence of any centralized leadership (the queen ant is merely an egg layer, not an authority figure) and each individual can only interact with a few nearby neighbors. Individuals have no way of assessing over all characteristics of the group, like size, goals or health. Instead the complex behaviors of the colony emerge from simple behavior of each individual.
Foraging behavior in harvester ants, for example, is a precisely timed and directed event, the properties of which are determined by simple rules of interactions between ants. Foraging is initiated in response to the rate at which patroller ants return to the colony. Once forager ants observe the correct rate of return they leave the nest following the scent trail of a returning patroller. The number of ants foraging is determined by how quickly ants return with seeds. Thus in a decentralized fashion the ants are able to ascertain that the external environment is safe for entry (based on the number of patrollers successfully able to leave and come back), the safest parts of the environment (by following the trails of successful returners) and adjust the resources devoted to foraging based on food availability (based on how quickly food is found).
So what does this have to do with us? We are too smart to have to use “swarm intelligence to accomplish complex goals. Instead we have LEADERSHIP (I mean surely G.W. is smarter than a swarm of ants)! Now lets imagine that a colony of humans had to accomplish the task of foraging for food for the colony.
First, the big boss says “We need food!”. Then after several years of federally funded research the academics decide that outside the nest is the best place to look for food. So the big boss sets up extensive panels to venture outside the nest to test whether this “theory” is actually real. Only after it has been exhaustively scrutinized by a group of the big boss’ friends (who don’t really understand foraging, anyway) can plans be drawn to start foraging. And then…. You get the picture, humans love hierarchy and most regulation of human group behavior is achieved through chains of authority.
Ant colonies (as well as many other group oriented organisms) use emergent behaviors (those that arise out of the multiplicity of simpler units) to construct complex behaviors as opposed to the hierarchical system favored by human groups.
So how does our brain accomplish complex behaviors from its colony of neurons?
To our knowledge there is no little brain (cerebellum aside) within our brain telling which nuclei to active when and where each axon should terminate. Instead we have billions of individual neurons that each only communicate with a relatively small subset of other neurons. Yet the brain is able to achieve coordinated thoughts like eating an apple.
To eat an apple or to even conceive of eating an apple, many disparate populations of neurons must somehow function together to produce a coherent thought. Different populations of neurons will follow their own specific sets of simple rules, just as ants will follow job dependent rules. Activation of P type retinal ganglion cells by the excitation of cones encodes the red color of the apple, while the sweet sensation of the apple touching our tongues is mediated by binding of simple sugars to GPCRs in taste cells, and the unique odor mediated by the odorant binding to a distinct pattern of olfactory receptors. Each of these neurons follow simple rules of firing and connectivity that when viewed in multitude, yield the emergent property of ‘apple thoughts’.
Some argue that the experience emerges from the milieu of electrical and chemical signals encoding ‘apple’ that is greater than the combined sum of the multitude of physical reactions; that the emergent pattern is our conscious perception of ‘apple’, which makes us more than a complex chemistry experiment. Others will assert that we are little more than just that, just as ant foraging behavior is little more than an algorithm of ant behavior.
Do our brains use ‘swarm intelligence’ to make us, uniquely us?
Something to ponder next time you see a line of ants raiding the cupboard.