Just accepted @EvolHumBehav: @HSB_Lab & I argue for social diversity during the Late Pleistocene w/ bigger groups, more hierarchy, etc. Preprint & summary in this older 🧵, so I’ll focus on how our argument differs from @DavidWengrow's #TheDawnOfEverything
Like @DavidGraeber & @DavidWengrow, we argue that the classic story (small, mobile, egalitarian bands before agriculture) needs a facelift. We point to some similar evidence (e.g., social flexibility & diversity among Holocene hunter-gatherers). Yet there are 4 major differences:
(1) We draw on (& embrace) behavioral ecology, which analyzes behavior using an evolutionary & ecological lens. In contrast to G&W, we argue that ecology shapes societies, w/ dense, reliable (esp. aquatic) resources more often sustaining larger, sedentary, stratified groups.
This is corroborated by comparative studies. See the plot (left) by Marlowe (2005): Across 340 forager societies, more fish means fewer moves/year. Or look at Codding & Smith (2020) (right): Across 89 Pacific Coast foragers, more aquatic resources predicts more hierarchy.
(2) We dwell on Africa. There are few direct signs of social diversity in Africa during the Late Pleistocene (~130k-12k yrs ago). So we turn to ecology. We synthesize research showing that ppl subsisted on resources (esp. coastal) that tend to sustain big groups, hierarchy, etc.
In fact, I'd argue it's hard to reconstruct Pleistocene societies w/o turning to diet & ecology. The basic problem is inferring past societies using recent analogues—yet how do we know which analogues to use? Behavioral ecology provides an empirically-informed framework.
(3) We argue there are implications for our evolved psychology. We conclude that human minds are not exclusively adapted for living in small, mobile, egalitarian bands. Rather, our psychology is much more flexible, equipped to traverse a much broader set of social circumstances.
Admittedly, G&W don't seem interested in implications for evolutionary understandings of behavior. Given how much the 'nomadic-egalitarian model' has impacted evolutionary anthro & evolutionary psych, however, we think that there's a lot of room for reconsideration here.
(4) G&W conclude that most of human history was characterized by 3 freedoms: freedom to move, freedom to disobey, & freedom to reconfigure social relationships. Presumably, these freedoms have largely disappeared. But there's little we've come across to suggest this narrative.
If anything, I wonder whether the story about the three freedoms replaces one 'noble savage' myth (nomadic-egalitarian) with another (über-free). But I look forward to empirical research that more systematically evaluates the claim.
Differences aside, our aims are similar: using archaeology + ethnography to question common assumptions about deep history & build better models. And regardless, G&W are forcing social scientists to contend w/ social diversity & flexibility in a way few big-picture thinkers have.
I've seen debate on here lately about Black Africans in the Greco-Roman world.
The best book on the topic is probably Frank Snowden Jr.'s "Blacks in Antiquity". Here's a recap of what he found:
Snowden Jr. focused on the period from ~600 BC to 400 AD. Greeks & Romans were clearly familiar with Black Africans, who they called "Ethiopians". They interacted most with the people of Nubia (then, the Kingdom of Kush, whose capital was Meroë for most of this period).
There are many indications of familiarity w/ Black Africans. Take artwork. Snowden Jr. argued that Greek & especially Roman artisans knew Black Africans intimately enough that they realistically depicted their features (rather than producing caricatures). Here are some examples:
Advocates of Paleo-inspired carnivore diets (e.g., @PaulSaladinoMD @SBakerMD) often point to the Inuit as having a traditionally carnivorous diet. Yet there are at least five problems with using the Inuit as the quintessential ancestral carnivores:
1. The Inuit lifestyle is relatively new. Human migrations into the Arctic occurred just a couple thousand years ago. If the idea is to return to an ancestral diet, they are arguably a less appropriate model than early agricultural populations who lived thousands of years before.
2. Inuit people ate plants. For example, in their intensive study of a Baffin Island community's diet in the 1980s, Kuhlein & Soueida found Inuit people eating kelp, berries, sorrel, & willow: https://t.co/MO9T8XA2xGsciencedirect.com/science/articl…
Did we evolve to respond to music? In our new @NatRevPsych article, @samuelmehr & I address this question, focusing on the universality, domain-specificity, & development of emotional & behavioral responses to music.
Starting with emotional responses, we review evidence of universality & early expression: People are pretty good at identifying emotions in foreign music (though culture still matters), & even infants can discriminate between some expressed emotions (see figure for ontogeny).
However, there is little research indicating that emotional responses evolved to be music-specific. Rather, we seem to express & recognize emotions in music using the same cognitive mechanisms involved in emotional communication in non-musical vocalizations like speech.
Stories of Spanish conquest in the Americas often focus on rapid events like the fall of the Aztecs or the capture of the Inca Atahualpa, creating the impression that conquest was fated. Yet look at the Maya, who took far longer to conquer, and a different story emerges.
To start: People often talk about a Mayan "collapse" in 900 CE. Yet Mayan civilization lived on. Yes, cities in the Southern Lowlands (see map) were abandoned, but other Mayan states prospered, especially in the Northern Lowlands (the Yucatan Peninsula).
Armed Spanish expeditions were sent to Maya lands starting in the 1510s. In 1524, after conquering the Aztecs & years after smallpox spread through Yucatan, Cortés marched there w/ an army. He got lost in the jungle & suffered huge casualties, though, and had to return to Mexico.
A trope of historical narratives is that superstitious natives believed European invaders to be gods. Yet the more I read, the more it seems these stories are post-conquest propaganda. Take the claim that the Aztecs (Mexica) thought Hernán Cortés was the god Quetzalcoatl.
You’re probably familiar w/ the standard story: The Aztecs believed that the feathered serpent, Quetzalcoatl, was destined to return from the east on a certain date. When the conquistador Hernán Cortés pulled up, they mistook him for the deity, making them easier to conquer.
This is popular. It appears in books like Todorov's "Conquest of America", along with a slew of history textbooks (search "Quetzalcoatl" here: historians.org/teaching-and-l…). Yet the evidence is tenuous.
In my recent @WIRED essay (wired.com/story/health-b…), I implied that there is little evidence of cognitive benefits of fasting. People have since sent me a lot of research, & I realize the story is more complicated. So here's what I've learned about how fasting affects cognition:
In thinking about effects, the 2 most important dimensions are: (1) The duration of fasting (e.g., 1/2 day fast vs 1 year of intermittent fasting) (2) The time-scale of effects (e.g., performance on the day of fasting vs cognitive performance after 6 months of fasting)
To start, cognitive performance seems to decline for single fasting events, esp if you don't normally fast. Here's a table from a review on short-term effects of fasting (refs below). Green means cognitive improvement, red means deficits. Most studies find deficits or no effects.