With his influential troika of books since 1991—The Third Chimpanzee; Guns, Germs, and Steel; and Collapse—Jared Diamond has shaped both the general public’s understanding of, and the academic research on, central topics of social science, including the roots of the success and failure of diverse societies in history. Whether or not you agree with his theories, there is no doubt that social science has gained much from his perspectives. He has refocused the attention of many on the long-run dynamics of societies, firmly anchoring modern inequalities and structures in deeply rooted historical processes. He has also set social scientists off on new empirical tracks, getting them to code datasets on the onset of the Neolithic revolution, the distribution of prehistorical crop and animal species, and archaic state formation—enabling researchers to look at how these factors correlate with modern economic growth.

After having had this sort of impact you might think an accomplished septuagenarian would be content to rest on his laurels and do a bit of basking. Not a bit. In his remarkable new book, The World Until Yesterday, Diamond is at it again, turning to a new set of questions and making all of us rethink what we thought we knew and understood.

Diamond’s earlier work, especially Guns, Germs, and Steel, was about how modern societies emerged, why some grew richer and more technologically advanced, and why some societies dominated others. In Collapse, he extended these ideas to address why some historical societies declined and perished. Both books were about what makes societies succeed or fail. His new book steps back and surveys the course of human history, seen primarily through the lenses of ethnography and anthropology, and argues that there may be important things to learn from any ethnographic or historical society independent of whether that society succeeded or failed in a larger sense.

Diamond strongly underscores that though some societies did grow richer and more technologically advanced than others, that does not mean they are “better.” Historically, societies have been organized in many different ways, and the idea of The World Until Yesterday is to use this huge variation in social organization as a lens through which to view the pros and cons of the modern world and to evaluate the institutions and social norms that structure Western society, particularly that of the United States. This evaluation is required, Diamond argues, because many societies might have been better organized in some dimensions than ours today. If we can learn from them, we can improve our own welfare.

An avowed environmentalist, Diamond has engaged in this exercise before, most notably in Collapse, where he pondered the consequences of global warming and environmental destruction for contemporary human societies. But the approach here is different and more subtle. The first few sections of The World Until Yesterday describe a range of issues that societies have addressed: dispute resolution, child rearing, old age, religious practices, diet, language, and the nature of friendship. For each topic, Diamond contrasts the attitudes and practices of modern Western societies to those of various “traditional societies”—mostly those observed by anthropologists over the past 100 years and some that he has studied firsthand.

The focus here is not on all types of traditional societies, but mostly on hunter-gatherer societies and tribes, to use the taxonomy of the late cultural anthropologist Elman Service, which Diamond introduces in the first chapter. Why this is the focus is not completely clear, because such societies are furthest away from the modern world. Nevertheless, his discussion shows that even within this cross-section there is enormous variation in practices and social norms. This overview brings out not only Diamond’s erudition, but also makes wonderful use of over 50 years of his own field research in New Guinea. Diamond was there mostly to study birds, but he seems to have been very aware of what the people were doing as well. As with all his books, the human stories in The World Until Yesterday, reflected in his own life, draw the reader in.

Diamond’s point in all of this is not to argue that one type of society is better in all dimensions than another, but to wonder whether we may have lost something along the way to modernity. Take our reaction to crying children. In Western societies we are taught that one should not pamper crying children and that they should be left to “get over it.” Diamond points out that in many traditional societies this is not the case and people respond to a crying child by picking her up and cuddling her. Which is the optimal response? Diamond does not propose an answer (which clearly depends on what criteria you are using), but he very effectively uses the anthropological evidence to make you consider the norms in our own societies and whether or not they could be improved.

The book is not content to take as a given the variation in social structures it highlights, and Diamond is at his best in proposing provocative and original theses to account for the variation—as he did in his past work. For example, he asks, why is it that some societies are willing to accept the spanking of children while others are not? His thought-provoking answer is that this is related to the types of economic activities the societies emphasize. The empirical fact is that hunter-gatherers tend to punish children less than do agricultural or herding societies. Diamond argues that this is because a wayward child in a hunter-gatherer society can only hurt himself, while in agricultural or herding societies, a child may cause greater damage—for example, letting a cow or goat escape. The greater potential costs lead to more severe punishments.

Dispute resolution provides another interesting instance in which the practices of traditional societies systematically deviate from our own. Diamond discusses an incident in New Guinea where a driver accidentally killed a child. He describes how the focus after the death was on restoring the relationships between people and families that the death had potentially sundered. In the modern world, the emphasis is on establishing right and wrong and extracting just compensation or applying the relevant legal sanctions. (Establishing right and wrong is relevant in New Guinea as well, but not so paramount.) Diamond explains here that modern systems of dispute resolution are based on very different principles from those typically at work in traditional societies. His goal is not to argue that one system taken en masse is superior to another, but rather to point out that part of the traditional perspective, that of restoring relationships, might be very desirable from a psychological point of view and might also work well, even in a modern world governed by states, anonymity, and social and geographic mobility.

Of course, the traditional societies Diamond discusses in the book did not have states, so there could be no such thing as criminal law because there was no state law to violate. This discussion raises the issue of why some parts of the world have states while others do not. Here Diamond retreats to the type of explanation he developed most notably in Guns, Germs, and Steel, arguing that states emerged earlier and most powerfully in places that made the first transitions to agriculture because they were fortuitously endowed with abundant domesticable plant and animal species.

His reassertion of this argument in this context is not fully satisfactory. He himself quite substantially weakened his thesis in the epilogue of Guns, Germs, and Steel. In it, he argued in favor of economic historian Eric Jones’s hypothesis, articulated in his classic The European Miracle, that the European economy advanced more quickly than China’s did because its fragmented state system fostered competition and technological change. In addition, reapplying Guns, Germs, and Steel’s hypothesis (albeit in a simpler version) is problematic here because the thesis and focus of that book was on intercontinental inequality and the developments before the early modern world (say the sixteenth century). But inequality between societies in the modern world is not shaped by intercontinental differences. Much of the richness and variation Diamond focuses on here occurs within narrow geographical confines and certainly within the same continents. For instance, one hunter-gatherer group he frequently discusses is the Siriono people of Eastern Bolivia. Though he does not explicitly discuss this in the Siriono context, the thesis of Guns, Germs, and Steel implies that their economy and institutions are consequences of the nature of their environment and its agricultural potential. But as Charles Mann points out in 1491: New Revelations of the Americas Before Columbus, the Siriono are sitting on top of vast unexcavated ruins of a pre-Columbian society that built elaborate causeways and canals and lived in towns surrounded by palisades and ditches—a society more advanced than the Siriono who populate the area today. Thus both states and hunter-gatherers actually can emerge in the same ecological niche. For that matter—and Diamond ignores this in his other work as well—why was it England (and then Britain), and not Denmark, Moldova, or Spain, all of which are in very similar ecological niches, that was at the forefront of modern state formation in the fifteenth century, and then of the institutional and industrial breakthroughs over later centuries?

Major changes in social organization, again apparent in his description of the dynamic richness of traditional societies, constitute another challenge to Diamond’s framework. Perhaps certain geographic factors have played a defining role in the early development of states (perhaps, but not likely, we argued in Why Nations Fail). But how do we explain such major patterns as China’s dominance in technology and prosperity in the fifteenth century, then its enduring economic and social backwardness for five centuries, and then its meteoric rise over the last 30 years? Any reasonable account of China’s economic and social history must place changes in the social organization and institutions of the country as the most important factor explaining these very significant ups and downs.

Diamond further extended his framework in Collapse, arguing that societies might fall apart because they suffered from the “tragedy of the commons” and a failure of people to cooperate. This insight might have clear relevance for several cases that Diamond discusses, including the endless conflict between the different factions of the Dani people in highland New Guinea, or that among the Nuer and between the Nuer and the Dinka in South Sudan. Such conflicts and the mostly ineffective ways in which they were resolved—by traditional judicial institutions, which used so-called leopard-skin chiefs to mediate disputes—surely influenced social and economic development in these societies, contributing to their relative poverty and economic backwardness. In fact, the problems of the Nuer and their inability to coalesce into a state might be a particularly compelling example of the tragedy of the commons. These problems are not just of historical or normative interest. Because the way traditional societies were structured casts a huge shadow over much of the modern world, Somalia, just to the east of Nuerland, and the world’s most recent state, South Sudan, will have to grapple with these problems for decades to come.

But Diamond is silent on why the tragedy of the commons is resolved in some places and not in others. Could it be that differences in social organization and institutions, rather than differences in geographic factors, are responsible for the different economic and social evolution of these societies? Could it be that these institutional differences will shape the future development of not just states and economies but also laws, customs, and familial structures in these societies?

There is a reason why Diamond might be shying away from such explanations, even though his rich description clearly calls for it: As he articulated in his review of our Why Nations Fail in The New York Review of Books, Diamond finds differences in social organization and institutions that cannot be traced more or less deterministically to geographic factors to be unsatisfactory, essentially “random.”

There’s a sense in which this is true. From the viewpoint of somebody looking at the world 10,000 years ago without omniscience, it would have been impossible to predict where institutional and technological revolutions would happen, and which parts of the world would become technologically and economically advanced. Who could have predicted in 1492 that today the United States would have living standards ten times higher than those of Guatemala, which had a far longer history of state formation and technological innovation at the time of the conquest? But this is not a justification for making social science slavishly dependent on geography. If it’s the case that institutional differences do emerge as a result of past practices and conflicts and evolve according to their own dynamics, and if it is the case that they are the major factor shaping every facet of society, then it is important to emphasize and account for it. Moreover, it might well be that even if we take geography out of the picture—again, as we argued in Why Nations Fail—one can have a scientific approach to these institutional dynamics, an approach where contingency and human innovation and creativity play a crucial role in explaining institutions.

The World Until Yesterday is precisely about the qualitative, and sometimes even quantitative, differences in social organization and institutions writ large, and Diamond explains why these differences matter better than anybody else. His discussion of this institutional variation would have been even further enriched by the development of a more explicit and positive theory explaining it, or at the very least, a recognition that such a theory is needed. This, ultimately, is a loss to social science, because a large part of the puzzle that Diamond himself put on the table is about why there is such richness in institutions, social organization, social norms, and outcomes in similar societies, and why many potentially desirable institutions, organizations, and norms have disappeared as we have transitioned from the traditional to the modern world.

In the end, even if he doesn’t really venture into these areas, Diamond distills a series of lessons about what we can learn from the practices of traditional societies that will most likely change the way we think about both these societies and our own. He succeeds—beautifully—in making us think about whether we might be able to raise our children better, look after our old people in more humane ways, adopt a healthier lifestyle, or respond better to disputes. He makes a credible case that we should preserve the linguistic diversity that still exists in the world and adopt a “constructive paranoia,” by which he means paying more attention to avoiding the risks of everyday life. Though there will be a lot of debate about these arguments and about what scientific evidence is relevant to assessing them, there is little doubt that Diamond has yet again shaped what we will all be debating in the next several years.