The world history class I am TAing is reading Guns, Germs, and Steel which I have talked about briefly before. I decided to read along with the rest of the class as I haven’t read the full book (only the beginning and the end). I should note that the professor doesn’t necessarily agree or disagree with Diamond’s work – I have no clue how she regards this book, in fact – but she believes it easily provokes debate and will help students engage the material in a more critical way. I completely agree as this post shows.
Rereading the prologue I noticed a glaring evolutionary just-so story. As Jared Diamond considers himself an evolutionary biologist, how he allowed this argument to be in the book I do not understand. I did a brief search on Google and I didn’t see any comments on this particular problem – most focused on the much more important issues with his work.
So what’s the issue? Basically, no evidence, i.e., what usually constitutes a just-so story.
As you may or may not know, Diamond opens Guns, Germs, and Steel with a brief anecdote about how a native New Guinean named Yali asks him why are Westerners so wealthy and nations like New Guinea so poor? Diamond extrapolates Yali’s question: “Why did human development proceed at such different rates on different continents?” (16). He claims that “the commonest explanation involves implicitly or explicitly assuming biological differences among peoples” (18). Okay, maybe that is what people think, but he cites nothing here – something we will continue to see.
He says that while this is the commonest explanation, it is most certainly wrong – when it comes to intelligence anyway. According to Diamond, no differences in intelligence have been detected between races (20). Instead, IQ tests test cultural learning instead of some absolute value. (I have no idea if IQ is real or not but I know there is some debate but as I haven’t investigated the topic at all, I won’t comment here. I’ll just grant Diamond this assertion for the purposes of the post.)
After saying, “the [evil!!!] psychologists’ efforts to date have not succeeded in convincingly establishing the postulated genetic deficiency in IQs of nonwhite peoples” (20), he then says “my perspective on this controversy comes from 33 years of working with New Guineans in their own intact societies.”
Anecdotal evidence, here we come!
He notes how intelligence is relative – New Guineans would look stupid to us if they visited a major US city and had to navigate our bureaucracy (as an example) but US citizens would look stupid (and probably die) if we found ourselves in a rainforest. Okay.
Then: “It’s easy to recognize two reasons why my impression that New Guineans are smarter than Westerners may be correct” (20). He had alluded to this in the previous paragraph – he believes New Guineans are “on the average, more intelligent, more alert, more expressive, and more interested in things and people around them than the average European or American is.”
Again, he had just said there is no IQ difference between races, but now New Guineans are smarter.
What? Where is the evidence for this assertion? Unless he’s being incredibly nuanced here and I missed it, I think he just contradicted himself.
Now for the just-so story:
Diamond notes that “Europeans have for thousands of year been living in densely populated societies with central governments, police, and judiciaries. In those societies, infections epidemic diseases of dense populations (such as smallpox) were historically the major cause of death, while murders were relatively uncommon and a state of war was the exception rather than the rule” (21). In contrast, New Guineans didn’t suffer through as many major diseases but dealt with murder and war on a much more consistent basis. Diamond claims that because of these differing scenarios, Europeans have been selected for body chemistry (resistance to disease) and New Guineans have been selected for intelligence (as smart people are more likely to not be killed).
While this scenario might be possible, Diamond offers no evidence nor citations for any part of the story. It is instead built upon assumption upon assumption and forces the reader to actively search for sources relevant to this complex topic. Has there been selection for body chemistry or intelligence in these peoples? and Is intelligence and murder-escape correlation or causation? are just two questions I have and Diamond provides me with no sources as a starting point. I think that is inexcusable.
As an example of body chemistry selection, Diamond claims that people with O or B blood types have greater resistance to smallpox than people with blood type A. Again, Diamond provides no evidence for this assertion. Many sites also claim this resistance but offer no sources as well. I did find this review article that questions the assumption. So… no idea what’s true and Diamond has done nothing to help.
I want to know this though: if O confers some resistance to smallpox, why were Native Americans (who are almost exclusively O) so decimated by the disease when Europeans arrived? Anyone have an answer? How does Diamond take this into account? Possibly the O blood type didn’t spread until after smallpox – O was selected for because of smallpox. I quickly found this article, however, that says O was predominant before European contact. (I have no time to read it at the moment though).
Diamond moves on to another reason New Guineans are smarter than Westerners – we watch TV. In contrast, New Guineans have more active entertainment or things to get done in general which promotes mental development. Again, no evidence on how this applies to his argument.
“This effect [active engagement on that part of New Guineans] surely contributes a non-genetic component to the superior average mental function displayed by New Guineans” (21).
Diamond writes this sentence declaratively, unambiguously, and again, without citation.
Is Diamond right? Are New Guineans more intelligent than Westerners? I have no idea. They could be, they could not be, they could be the same. The problem I wanted to point out is not that Diamond is right or wrong, but that he provides no evidence for his argument. He actually cites the section about IQ – the Bell Curve by Herrnstein and Murray – and notes that it is “the best-known or most notorious entrant into the debate about group differences in intelligence” (444). No page numbers and I don’t even know how it applies to his argument. In fact, this isn’t really a citation at all, but “further reading.”
What is this? Unless I’m totally wrong, Jared Diamond has just put forth a scientific argument that isn’t scientific at all – a definitive just-so story. I even had to search for evidence of the blood type resistance claims myself. Yes, this is a book for a popular audience, but it is also for an academic audience and we should expect a more rigorous citation system when it comes to the authoritative statements Jared Diamond makes here.
Is this really a problem? I think so. Even though this story is only a few pages long, I think it hurts his overarching argument. He contradicts himself and then proposes some selection story without evidence – didn’t he read any SJ Gould? Diamond would have been better off just cutting the section, in my opinion.
Diamond’s just-so story is completely unnecessary and negatively affects how I I will view the rest of the book. Uncited generalizations abound with a lack of rigor and clear thought. I am sympathetic to Diamond’s goal – searching for ultimate causes to explain the the state of the world today rather than proximate causes – but my skepticism is now on guard (as it should be anyway).
Diamond, Jared. Guns, Germs, and Steel (1997).