These Cro-Magnon field notes would flesh out Darwin’s early evolutionary analysis of our moral capacities. A clear picture of early hominid social life would tell us of the recurring social contexts that reduce the chances of genes making it to the next generation—the perils of escalated aggression between males, the prevalence of infidelity and strategic cuckoldry, the reduced likelihood of offspring surviving if fathers are not engaged. We would also read of the social tendencies that increase the chances of gene replication—the sharing of food or caring for offspring, social strategies that allow females and males to rise in social hierarchies, thereby gaining preferential access to resources and mates. Knowing these social facets of the EEA would then lay a platform for understanding the deeper origins of where the blush of embarrassment comes from, why we can communicate pro-social emotions like gratitude or compassion by one-second touches to a stranger’s arm, how devoted love is represented in the flow of certain neuropeptides in the bloodstream.
Absent these Cro-Magnon field notes, we can turn to several kinds of evidence, and a Darwinian capacity for going beyond the information given, to envisage our EEA. We can turn to studies of our closest primate relatives, chimpanzees and bonobos in particular—with whom the human species shared a common ancestor some seven to eight million years ago. Here similarities in social existence—caregiving or hierarchical organization, for example—tell us about basic primate social tendencies and the organization of the pro-social branches of the nervous system. Differences—for example in pair bonding patterns—uncover likely sources of the specifics of human design, and new dimensions to our emotional life.
We can turn to the scanty archaeological record of human ancestry. Here exciting debates are clarifying the meaning of piles of animal bones near ancient hearths, shifts in skeletal structure in the predecessors of
Finally, we can rely on the detailed observations of contemporary hunter-gatherer societies in remote places in the Amazon, Africa, and New Guinea. These rich descriptions of hunter-gatherer social life—studies of the !Kung San of southern Africa, for example—provide hints into what day-to-day life might have been like for our hunter-gatherer predecessors tens of thousands of years ago.
If we had those Cro-Magnon field notes, we would read that our hominid predecessors spent most of their minutes alive in the presence of other group members, living in close proximity in thirty-to seventy-five-person groups. Division of labor was pronounced: Females served as the primary gatherers of food and caretakers of infants during the extended period of immaturity, traveling less than males, who would have devoted much of their time to the tasks of hunting—flaking stones for weapons, carving spears, tracking game, sharing information about migration patterns and moments of prey vulnerability. Our Cro-Magnon writer, though, would have to have taken note of the relative similarity in size of females and males (the average difference in size between modern human males and females is about 15 percent; in the hominid species that preceded our immediate predecessor, males were about 50 percent bigger than females) and the competition between males for access to mates that would have produced this leveling off of size differences between the sexes.
Several chapters would reveal the darker side of our hominid predecessors, and the origins of the disturbing tendencies of contemporary humans. Here the Cro-Magnon anthropologist would have ample data to write about the regularity of male-on-male violence. There would be extensive observations about warlike behavior, and raids on other groups that might give rise to murder and rape. The regularity of strategic infanticide would emerge as a theme.
At the same time, our Cro-Magnon anthropologist would write specific chapters about social dimensions of the lives of our hominid predecessors that would illuminate the origins of emotions like embarrassment, compassion, love, and awe, and our early capacity for
TAKE CARE OR DIE
The first chapter of the Cro-Magnon field notes would be devoted to the prevalence of caregiving, a hallmark feature of higher primates. As Frans de Waal has observed, chimpanzees and bonobos often become wildly distressed when witnessing harm to other group members. Chimps and bonobos routinely protect conspecifics born blind. They shift their play, resource allocations, and physical navigation of the environment when interacting with fellow primates crippled by physical abnormalities. They, like us, are attuned to harm and vulnerability, and tailor their actions accordingly.