The Evolution of Agency – Part 3

Sociality led to the highest forms of agency.

Continuing this series of essays, we’ll explore the evolutionary origins of human agency, the key steps in that development, and the need for society to uphold the types of social arrangements that made the development of human agency possible in the first place.  Michael Tomasello, in his book The Evolution of Agency: Behavioral Organization from Lizards to Humans, writes:

[W]hy have only some species, for example, mammals, developed sophisticated skills of executive decision-making and inhibitory control? The answer, I believe, lies in mammals’ new form of social complexity. Reptiles interact with other animate creatures mainly as predators and prey, and apparently their flexible skills of goal-directed agency are sufficient to deal with the ensuing uncertainties. But mammals live in social groups with conspecifics, and this means at least two things. First, individuals must engage in their normal foraging activities especially efficiently, because if they do not, their group mates will scramble to all the resources first (scramble competition). This may involve inhibiting pursuit of the closest resource if a competitor is closer to it. Second, individuals sometimes compete over resources with others directly (contest competition), so they must figure out whether and how to fight, with signals of dominance helping the decision. If they are competing with a stronger individual for a resource, they must inhibit their desire to go directly for it … Two empirical studies support this special version of the social complexity hypothesis. First, Johnson-Ulrich and Holekamp (2020) gave a version of the detour (cylinder) task to five clans of spotted hyenas that varied in size and demographic makeup. The study found that hyenas living in larger groups—specifically, individuals who grew up in larger cohorts as juveniles—had greater skills of inhibitory control. In addition, low-ranking hyenas, who must frequently inhibit both feeding and aggression in the presence of higher-ranking hyenas, had the strongest inhibitory skills of all … Second, Amici et al. (2008) investigated seven different primate species with different levels of social complexity, as indicated by the degree to which their social organization reflected a fission-fusion dynamic (in which the larger group splinters into smaller parties, which then reassemble into different parties throughout the day). The researchers hypothesized that this dynamic would require individuals especially often to exhibit inhibitory control in foraging and other activities. Supporting this hypothesis, they found that fission-fusion dynamics were positively associated with enhanced inhibitory skills (as measured by five different tests of inhibitory control) … The most likely hypothesis is that mammals evolved these skills as instruments of cognitive monitoring and control to keep the execution of their plans and intentions on track, which had special importance in the context of complex social groups that created social competition of various kinds.

Rapidly changing environments, along with cooperative strategies to deal with them, supercharged the development of agency in mammals:

Although learning is often opposed to “innate” or hardwired behaviors, the fact is that learning is itself a biological adaptation that may evolve with different features. Boyd and Richerson (1985) have argued and provided evidence that learning as an adaptive strategy arises in a species (or in particular contexts within a species) in the face of environments that change rapidly and unpredictably, such that hardwiring is too rigid to guide effective action consistently. This description accords well with the current account of the ecological conditions in response to which agency in general, and executive functioning in particular, evolved … With the emergence of mammals some 200 million years ago, then, came a new form of psychological organization: intentional agency as empowered by a new tier of executive functioning. Intentional agents are able to think and plan before they act; that is, in many situations, they are able to cognitively simulate the actions they might perform and to evaluate these action plans to decide which of them to execute and how, such as in some particular sequence, perhaps involving goal embedding. Then, as they proceed to execute the chosen plan, they cognitively monitor the process and keep things on track even if they encounter surprises along the way, for example, by monitoring and adjusting to uncertainty in a decision or by inhibiting any unplanned actions that threaten to disrupt action execution. This cognitive monitoring also enables them to learn how their actions affect environmental situations, which may be useful either to adjust in the moment or to store for future use. This flexibility and learning evolved so that individuals were able to act effectively in response to whatever novel contingencies might come their way, including those generated by unpredictable instances of social competition.

The rise of the great apes showed the way:

[G]reat apes’ especially intense competition for food led them to reflective forms of decision-making and cognitive control; that is, they began to make more efficient decisions by employing a second-order tier of executive (reflective) functioning, creating new ways of planning, choosing, and controlling their actions. Operating logically and reflectively in these ways means that ancient great apes evolved a new organization for psychological functioning: rational agency … If great apes are already rational agents, what further form of agency could possibly be open to humans that would account for the many species-unique products and ways of life—involving complex technologies, complex symbol systems, and complex cultural institutions—that enable them to completely dominate the large-mammal niche on planet Earth? The answer involves one of evolution’s oldest tricks, just on a new level. During the past three billion years of life on the planet, a handful of major transitions have occurred in the organization of life-forms, for example, the emergence of chromosomes, the emergence of multicellular organisms, and the emergence of sexual reproduction. In each case the transition occurred in the same basic way: previously independent entities came together to act as a single unit. The emergence of humans and their domination of other mammals fit this same general pattern: individuals came together to form socially shared agencies—socially constituted feedback control systems—that could pursue shared goals that no individual could attain on its own … Modern human individuals formed with others in their cultural group a collective agency … Socially shared agencies challenged early humans with many new unpredictabilities, requiring many new psychological adaptations … What could be riskier and more uncertain than forgoing pursuit of one’s own individual goal to try to align and coordinate toward a common goal with a partner who has her own individual goals and values? And the risks and uncertainties are only magnified when the “partner” is an entire cultural group. Making these new socially constituted forms of agency work thus required ancestral humans to develop both new skills of social coordination and new social motivations.

The result of this process was early humanity:

[T]hese complex, socially shared agencies have worked spectacularly well for humans—at least so far—leading to a highly successful species with all kinds of new individual skills and motivations, not to mention all kinds of group-level achievements … A beginning might have been scavenging meat from carcasses, which would likely have required a kind of coalition of individuals to frighten off other animals interested in the same food. But at some point, early humans began to collaborate more actively in hunting large game and procuring some plant foods, typically in mutualistic stag hunt type situations in which both individuals could expect to benefit from the collaboration if they could somehow manage to coordinate their efforts. This pattern is especially clear in early humans of about four hundred thousand years ago—the common ancestor to Neanderthals and modern humans … In a stag hunt situation, individuals must collaborate with others to benefit, and the benefits are greater than those of any solo alternatives (which must be forsaken or at least risked). As early humans began obtaining the majority of their food via such collaboration, it became obligate, so that individuals became dependent on one another—they became interdependent—in especially immediate and urgent ways. Another dimension of this interdependence was partner choice. Individuals who were not skilled at collaboration—for example, were unable to communicate effectively—were not chosen as partners. Similarly, individuals who were not cooperatively motivated—for example, tried to hog all the spoils—were also shunned as partners. The upshot was that there was extremely strong social selection for cooperatively competent and motivated individuals.

In the next essay in this series, we’ll explore the key social guardrails that led early humans to the highest form of agency.