Lixing Sun in Nautilus:
Did the ancient Athenians invent democracy? Or did bugs have it way earlier than the Greeks? Cornell entomologist Tom Seeley knows which option he’s voting for.
Honeybees regularly split from their mother colony. Seeley wondered, with tens of thousands of bees in a swarm, how do they reach agreement? His answer: simple-majority democracy.
In his 2010 book Honeybee Democracy, Seeley described how bees intending to strike out on their own first send scouts in all directions to collect information. On their return, these early scouts buzz and twirl to recruit more scouts. Some gain fans whereas others lose them. Newly deciding scouts go out to look for themselves. After the majority of scouts (which number in the hundreds) have converged on one opinion, the entire swarm takes off for its promised land.
Bees are not alone in using simple-majority rule—Tibetan macaques do it too. In 2014, my colleagues and I were studying how a group of 12 adult macaques coordinated their collective movements. We noticed that once three or more of them ganged up together, the entire group would often follow suit. The success rate in getting the group into action increased with the number of initiators—those who started the process. When the initiators numbered seven or more, exceeding a simple majority, the success rate reached its maximum: 100 percent.
Democracy in collective decision-making has also been observed in African buffaloes, red deer, baboons, and pigeons. Even single-celled bacteria make collective decisions based on a democratic process known as quorum sensing. Their genes control some aspect of their behavior, like how mobile or virulent they should become, based on how many of their bacterial comrades are already engaging in that behavior. Similar democratic processes are also used by cockroaches and other swarming insects.