Ants and humans

Discovery News recently posted this article about the growing resemblance between human societies and ant colonies. In a recent post I mentioned Dunbar’s number, which is believed to be a limit on the number of social relationships a single person can have, and thus indirectly a limit on group size. Chimpanzee groups typically contain 15 to 150 individuals and are based on personal relationships. The largest human groupings (e.g., cities, nations) can be much larger, and the individuals who belong to them do not need to know each other, which makes us more like ants than chimps in this respect.

Ants use pheromones for communication between strangers; we use various symbolic cues to communicate our affiliations. Because our groups are so huge, we have to solve problems that chimps never face (building and maintaining infrastructure, for example, or complicated teamwork) but that ant colonies have had to contend with. This is interesting in light of Edward O. Wilson’s thoughts on eusocial species, including ants and humans (eusociality being both relatively unusual and very successful). Ants have been at it longer than we have and may have developed solutions that we could learn from. On the other hand, maybe not, because we’re not nearly as selfless as they are (Wilson described them as “angelic robots” in the talk I heard, which we most definitely are not and would not want to be). Another interesting point is that while the size of groups based on personal relationships appears to be dictated by Dunbar’s number or something like it, the growth of large, complex groups like ant colonies and most of today’s human societies is thought to be limited only by environmental conditions. That’s probably more of a limitation for ants than for humans, who can manipulate environmental conditions to some degree (although it’s not always wise for us to do so).