On the origin of forager bands
This analysis suggests that the transition from the closed social worlds characteristic of the great apes species to open bands nested in a larger community began quite early, with the erectines or the more clearly apex hunters, the Heidelbergensians (Stiner 2002). Layton and his colleagues suggest that long distance raw material transport is a proxy for more open networks. If raw material movement regularly and comfortably exceeds the plausible daily movement limits of a band, the social world is probably open enough to allow material resources to flow from one band to another, or for bands to allow movement by others into their territories to harvest stone or ochre (Layton and O’Hara 2010, Layton, O’Hara et al. 2012). This proxy suggests a quite deep origin of open-textured social organization, probably with the Heidelbergensians (about 800 kya).
Kim Sterelny, The Pleistocene Social Contract, p. 108
The Cultural Origins of the Demographic Transition in France
Across départements, I estimate a strong and robust positive association between the presence of refractory clergy and the timing of the transition using census data available from 1831 to 1961. The regions that secularized experienced a decline in fertility more than a century earlier than those that did not—no other variable has an impact nearly as important. The difference between Provence, a stronghold of secularization, and Brittany, a bastion of Catholicism, is as large as the difference between France and England.
Additionally, I study the heterogeneous effects of the refractory clergy and find that cultural and economic factors played complementary roles. The correlation between secularization and the decline in fertility is larger in more densely populated places, suggesting that the relaxation of moral and social constraints allowed individuals to reach their desired level of fertility— which was lower in more developed regions.
Is it good to cooperate?
What is morality? And to what extent does it vary around the world? The theory of “morality-as-cooperation” argues that morality consists of a collection of biological and cultural solutions to the problems of cooperation recurrent in human social life. Morality-as-cooperation draws on the theory of non-zero-sum games to identify distinct problems of cooperation and their solutions, and it predicts that specific forms of cooperative behavior—including helping kin, helping your group, reciprocating, being brave, deferring to superiors, dividing disputed resources, and respecting prior possession—will be considered morally good wherever they arise, in all cultures. To test these predictions, we investigate the moral valence of these seven cooperative behaviors in the ethnographic records of 60 societies. We find that the moral valence of these behaviors is uniformly positive, and the majority of these cooperative morals are observed in the majority of cultures, with equal frequency across all regions of the world. We conclude that these seven cooperative behaviors are plausible candidates for universal moral rules, and that morality-as-cooperation could provide the unified theory of morality that anthropology has hitherto lacked.
Zero-sum thinking, the evolution of effort suppressing beliefs, and economic development
We study the evolution of belief systems that suppress productive effort. These include concerns about the envy of others, beliefs in the importance of luck for success, disdain for competitive effort, and traditional beliefs in witchcraft. We show that such demotivating beliefs can evolve when interactions are zero-sum in nature, i.e., gains for one individual tend to come at the expense of others. Within a population, our model predicts a divergence between material and subjective payoffs, with material welfare being hump-shaped and subjective well-being being decreasing in demotivating beliefs. Across societies, our model predicts a positive relationship between zero-sum thinking and demotivating beliefs and a negative relationship between zero-sum thinking (or demotivating beliefs) and both material welfare and subjective well-being. We test the model’s predictions using data from two samples in the Democratic Republic of Congo and from the World Values Survey. In the DRC, we find a positive relationship between zero-sum thinking and the presence of demotivating beliefs, such as concerns about envy and beliefs in witchcraft. Globally, zero-sum thinking is associated with skepticism about the importance of hard work for success, lower income, less educational attainment, less financial security, and lower life satisfaction. Comparing individuals in the same zero-sum environment, we observe the divergence between material outcomes and subjective well-being predicted by our model.
The Outlook for Long-Term Economic Growth
What are the prospects for economic growth in the United States and other advanced countries over the next several decades? U.S. growth for the past 150 years has been surprisingly stable at 2% per year. Growth theory reveals that in the long run, growth in living standards is determined by growth in the worldwide number of people searching for ideas. At the same time, a growth accounting exercise for the United States since the 1950s suggests that many other factors have temporarily contributed to growth, including rising educational attainment and a rising investment rate in ideas. But these forces are inherently temporary, implying that growth rates could slow in the future. This prediction is reinforced by declining population growth throughout the world. In contrast, other forces could potentially sustain or even increase growth. The emergence of countries such as China and India provides large numbers of people who could search for ideas. Improvements in the allocation of talent — for example, the rise of women inventors — and increased automation through artificial intelligence are other potential tailwinds.
Human ancestors nearly went extinct 900,000 years ago
Human ancestors in Africa were pushed to the brink of extinction around 900,000 years ago, a study shows. The work, published in Science, suggests a drastic reduction in the population of our ancestors well before our species, Homo sapiens, emerged. The population of breeding individuals was reduced to just 1,280 and didn’t expand again for another 117,000 years.
Nick Ashton, an archaeologist at the British Museum in London, who wrote a related perspective, says he was intrigued by the tiny size of the population. “This would imply that it occupied a very localized area with good social cohesion for it to survive,” he says. “Of greater surprise is the estimated length of time that this small group survived. If this is correct, then one imagines that it would require a stable environment with sufficient resources and few stresses to the system.
This period was part of the Early-Middle Pleistocene transition — a time of drastic climate change, when glacial cycles became longer and more intense. In Africa, this led to long periods of drought. Li says that the changing climate might have wiped out human ancestors and forced new human species to emerge. Eventually, these might have evolved into the last common ancestor of modern humans and our extinct relatives, the Denisovans and Neanderthals.
Around 813,000 years ago, the population of pre-humans began to swell again. How our ancestors managed to survive, and what allowed them to flourish once more, remains unclear, says Ziqian Hao, a population geneticist at the Shandong First Medical University and Shandong Academy of Medical Sciences in Jinan, and a co-author of the paper. However, he says that the bottleneck is likely to have had a crucial impact on human genetic diversity, driving many important features of modern humans, such as brain size. He estimates that up to two-thirds of genetic diversity was lost. “It represents a key period of time during the evolution of humans. So there are many important questions to be answered,” he says.