How the Social Thinks: Of Bees and Brains
Psychophysics is an important domain for cross-species analysis. The field discerns a series of laws that govern how human brains process the relationship between stimulus intensity and perception; these can then be found operating similarly across a spectrum of taxa—mammals, fish, birds and insects. The latter are particularly intriguing, since they can be seen to displays cognitive abilities comparable to higher order life forms. Recent work by Reina et al. develop parallels between superorganisms like bee colonies and the human brain, in terms of fundamental mechanisms of information processing and decision making. Colonies’ decisions on a location for a new nest follow similar dynamics to human decision making—these come quicker when two options are both of high quality (Pieron’s Law), slower when the number of alternatives increase (Hick’s Law), and settle on the best option when the differences between them are minimal (Weber’s Law). Their conclusion is notable: “A large number of organisms at diverse levels of biological complexity, from humans to unicellular moulds, obey the same psychophysical laws that characterise the relationship between stimuli and the organism’s response.” Human thought has a great capacity for variation, but much of it might just come down to to some very simple dynamics that we share in common with other species.
This finding is important for theorizing sociality in a cross-species frame, because the researchers formulate this process in terms of a “group of individuals” (bees) viewed as a colony (superorganism) thinking like humans do. The human brain is often heralded as clear evidence of the uniqueness of humans, though our brain-size scales on a brain-body-social relationship in a fairly uniform manner with other mammals. Apparently, though, that complexity rests upon a few simple principles by which stimuli are processed and collective decision rendered. This recognition upends a central pillar of the idea of human uniqueness by binding us to creatures that lack our brain power but are similarly constituted as social subjects in complex societies where the division of labor is evident. As well, it considerably opens up communication as a medium: bees may “speak” with each other much the way our neurons do. If so, by what conventions and systems? Where else might parallels between human brains and bees lead? The effort to develop an “anthropology beyond the human” has focused on recognizing thinking as occurring in nonhuman subjects—as in Eduardo Kohn’s, How Forests Think. Though it has entirely overlooked the enormous amount of work on animal cognition, perhaps we are nearing a moment of increased interdisciplinary dialogue. This development in anthropology needs to start drawing from research on thought processes in nonhumans; but it also has good deal potentially to contribute to such lines of inquiry. For in humans, brains are not just the property of individuals. Our thought is fundamentally social; our capacity to express thoughts through language is entirely cultural, as are the “voices” we often respond to as we’re thinking. Is this the case with cognition among social species generally?
Reina et al are not thinking in these terms. They largely promote the value of their research as a means of transposing the purported dynamics of neurons to a setting that’s far easier to observe—bee colonies, in this case. As Reina explains: “Finding similarities between the behaviour of honeybee colonies and brain neurons is useful because the behaviour of bees selecting a nest is simpler than studying neurons in a brain that makes decisions.” Simpler, presumably, but still social. Synapses are shaped via social stimuli and in reaction to social relations. If brains and bee colonies work similarly, is it because of their social dynamics? Quite likely, based on these findings: “Similarly to neurons, no individual explicitly encodes in its simple actions the dynamics determining the psychophysical laws; instead it is the group as a whole that displays such dynamics.” The trick then lies in not reproducing the “individual” as model for the human brain; asking instead, about parallels in social signaling and interpretation that produces such law-like operations at a variety of scales of sociality.
Andreagiovanni Reina, Thomas Bose, Vito Trianni, and James A. R. Marshall, “Psychophysical Laws and the Superorganism,” Scientific Reports 8, no. 1 (2018): 4387, https://doi.org/10.1038/s41598-018-22616-y.
Through theoretical analysis, we show how a superorganism may react to stimulus variations according to psychophysical laws observed in humans and other animals. We investigate an empirically-motivated honeybee house-hunting model, which describes a value-sensitive decision process over potential nest-sites, at the level of the colony. In this study, we show how colony decision time increases with the number of available nests, in agreement with the Hick-Hyman law of psychophysics, and decreases with mean nest quality, in agreement with Piéron’s law. We also show that colony error rate depends on mean nest quality, and difference in quality, in agreement with Weber’s law. Psychophysical laws, particularly Weber’s law, have been found in diverse species, including unicellular organisms. Our theoretical results predict that superorganisms may also exhibit such behaviour, suggesting that these laws arise from fundamental mechanisms of information processing and decision-making. Finally, we propose a combined psychophysical law which unifies Hick-Hyman’s law and Piéron’s law, traditionally studied independently; this unified law makes predictions that can be empirically tested.