A Tentative Defence of Guns, Germs and Steel
Jared Diamond's Guns, Germans & Steel (GG&S) is highly flawed. Almost every big picture book is, to a degree, and this one particularly so.
But I believe GG&S has become a punching bag to signal holier-than-thou historian cred or something. I think nowadays most people railing against him haven't even read the book, but have read some Reddit FAQs. The entire section around the battle of Cajamarca is flawed and bad history, but it's also not what the book is about, barely acts as evidence for his thesis and is more a rhetorical flourish trying to bring themes together. It is easy to read the book, read some critiques, and separate the chaff from the wheat.
So here I'm offering a tentative defence of the book.
Diamond's Credentials
Firstly, I want to discuss Diamond's credentials. I see many random commentariat (speaking as a random commentarian) taking issue with Diamond's "area of expertise," which they mock as limited to birds. Their own area of expertise is of course rarely raised.
I believe people are more than their undergrad degrees. Diamond got his PhD in 1961, almost forty years before GG&S was published. That is a lot of time to develop a career and get a lot of experience. It is not completely wild to go from writing about extinction risks to human caused extinction events to human impacts on biogeography, and then talking about how specific cultures interact with their environment and then writing a book about how geography impacts human society.
This is a summary of his trajectory:
"Dr. Jared Mason Diamond, Professor of Physiology at the University of California Los Angeles School of Medicine, has made remarkable achievements in physiological studies on biological membranes and others, which have been recognized by election to the National Academy of Sciences. At the same time, pursuing a parallel career in such other areas as evolutionary biology and biogeography based on fieldwork, he has organized more than 15 expeditions, mainly to New Guinea, for over 30 years, and published many papers on the relationship between living things in nature, centering on birds and humans.
With the results of those field expeditions as the bases, Dr. Diamond's interest broadened and he turned his attention more and more toward global human ecology"
What is Guns, Germs and Steel actually about?
I think GG&S is best read as answering basically the question he sets up at the start: why were the people from the Eurasian-North African Megaregion able to conquer North America, Mesoamerica, South America, Africa, Oceania and the rest of the globe instead of vice versa.
Looking through the AskHistoriansFAQ one of the first links recommends in place of GG&S, books such as The Last Days of the Inca and Seven Myths of the Spanish Conquest. But to me, that simply isn't what GG&S is about. If you want to know about the Spanish conquest of the Americas then yes, steer clear of it. For some perspective, GG&S's discussion of "why Europe and not China" is an afterthought relegated to the epilogue. If European conquest is an afterthought, don't even begin to dive into the particulars of specifically Spain.
It's why I call the [particularly problematic] chapter on the Battle of Cajamarca a rhetorical flourish. That battle doesn't matter. Why the Spaniards won there doesn't matter. What matters is the fact that there were literally hundreds of battles, all across the globe, over hundreds of years, and despite the occasional loss these were steadily won by people originating from the Eurasian-North African Megaregion, and not vice versa. I think it's a decent contribution to understanding why, especially with the subsequent thirty years of responses to it.
I believe he pushes his argument too far, but I expect that of most books trying to make a specific argument, so it doesn't bother me that much. I similarly find Why Nations Fail's discussion extending the institutions argument to prehistoric societies entirely unconvincing. Diamond's responses to the responses to GG&S are particularly less satisfying than the initial work, because I think he's pushing back too much on valid critique rather than assimilating the additional information. However, if you read the book as laying out an initial argument, which is now over thirty years old, you will have enough scepticism and humility to not take every word as an article of faith.
As an aside, my personal synthesis of GG&S and other works (such as Why Nations Fail, The Narrow Corridor, Why the Rest Rules For Now, Sapiens How the World Made the West, The Silk Road etc) is that one way to view """human progress""" is precisely in the extent of our ability to bend the natural world to our will, through the application of knowledge. This knowledge is enhanced and brought to scale through science, institutions and material investments. So as human society """progresses,""" almost by definition, geography becomes less important and institutional factors more relevant.
A specific response to a specific paper
What has actually triggered this decades out of date defence, was in fact seeing a particular paper: Geography is not destiny: A quantitative test of Diamond's axis of orientation hypothesis.
To be up front, I am not terribly stats-minded, but this paper weighed on me and I believe it shows why a quantitative/statistical approach to history can be severely limiting.
The gist of the paper, as per its abstract:
Jared Diamond suggested that the unique East–West orientation of Eurasia facilitated the spread of cultural innovations and gave it substantial political, technological and military advantages over other continental regions. This controversial hypothesis assumes that innovations can spread more easily across similar habitats, and that environments tend to be more homogeneous at similar latitudes. The resulting prediction is that Eurasia is home to environmentally homogenous corridors that enable fast cultural transmission. Despite indirect evidence supporting Diamond's influential hypothesis, quantitative tests of its underlying assumptions are currently lacking. Here we address this critical gap by leveraging ecological, cultural and linguistic datasets at a global scale. Our analyses show that although societies that share similar ecologies are more likely to share cultural traits, the Eurasian continent is not significantly more ecologically homogeneous than other continental regions.
For me, part of Diamond's point is that, and we know this as historical fact, oranges were domesticated in China, moved to India, moved to the Middle East and then formed a part of the Spanish economy as part of the Arab agricultural revolution in the ~900-1200s. This could happen because, despite being >10,000 km away, oranges grow well in both south China and Spain. Part of the reason why they grow well in both regions, Diamond posits, is that they are at the same latitude.
So we also know, as a matter of historical fact, that a transfer of oranges did not occur between China and the much closer Yakutsk. Obviously and non-controversially, as oranges don't grow well in Siberia. Thus Spain could benefit from agricultural development in China in a way Siberia could not. For Spain this is true for many core agricultural goods, including olives and wheat. It grew into an urban, agricultural, flourishing region in part due to these imports.
Diamond's argument is therefore that, because there is more landmass along a similar latitude in the Eurasian-North African Megaregion, there is more opportunity for this sort of lateral spread of agriculture and basic civilisational innovation, as compared to regions oriented North-South.
To me this is fairly simple and compelling narrative.
The study on the other hand has a lot of data and methodology. You pick a society in, say, the middle east, you find it's closest 100 neighbours that are at least >2,500km away, and you find the "cost" of the distance in terms of differences in aridity, topography and temperature, and then you average this cost out to find the "harshness" of diffusion from this middle eastern centre.
So from the supplementary materials, we see the "cost" of travel from the Middle Eastern origin of agriculture to surrounding areas:
And so by doing this, we have - as a consequence of our parameters - left out that Spanish agriculture was deeply interconnected with the Levant entirely. The study doesn't have a single society on the Iberian peninsula that is examined. But we do see that there were a numerous societies in sub-Saharan Africa, but it was very, very costly to travel to them. So thus we can say that diffusion "from" the Middle East was very costly, thus diffusion in Eurasia was very costly. As far as I can tell, very ironically, this is precisely because the North-South axis is costly!!
If I look at, say, the Andes, it isn't connected to North America at all in the analysis, because it's too far away (or, because there are too many societies closer south!)
Was North America limited by not being able to transplant agriculture from the Andes? This study doesn't tell us. Just that based on topography, aridity and and temperature that travel around the Andes is similarly diverse ("costly") as travel around the Middle East (including South through the Sahara...).
And what are we measuring in terms of diffusion? It isn't simply foundational things, such as "wheat," which could be rapidly transported vast distances by, say, ship. It is instead examining cultural similarity with variables such as whether the same games are played or if there are similar marriage customs.
Spain did not have similar marriage customs to China, thus the study concludes that there was little impact on one to the other. Our knowledge of the economic interchange along the Silk Road and the Mediterranean as a commerce mega-highway be damned!
I'd be very curious to re-run the study with some of the variables tweaked to actually divide the world into the mega-regions of Eurasia-and-North Africa, the Americas, Sub-Saharan Africa, and Oceania.