The Germ of Laziness

That happens to be the title of a pretty interesting book about hookworm in the US.  The book was fine, but the story is better.

Hookworms are parasitic nematodes that take up residence in the small intestine and drink your blood.  Getting there is complicated. Eggs are shed in the stool, hatch in to larvae in suitable soil, and enter the next host through bare feet. They then migrate (through the blood stream)  to the lungs, then to the trachea, where they are swallowed and eventually reach the small intestine.

Enough of them can cause significant blood loss and serious anemia.

They have been a particular problem among miners, wading in wet tunnels, and an epidemic among workers  in an Italian railway tunnel 1880 led to general medical understanding – other people had  figured some of this out earlier, sometimes much earlier (Theodor Bilharz, even Avicenna!) but that knowledge did not become general.

Charles Wardell Styles , who had studied  parasitology at the Institute Pasteur and gotten his Ph.D. at Leipzig, discovered that hookworm was common in the American South.  People thought differently in those days: he tried to abolish hookworm.  That was harder that he expected.  Southerners claimed that they couldn’t possibly have such a disgusting problem – it was just Yankee slander.  M.D.s ( back then, before the Flexner reforms, med school was often a six-month course) pointed out that he wasn’t even a doctor, so why should they listen to him?  After giving one talk, two M.D.s wondered if actually getting  rid of hookworm, curing the disease –  wouldn’t that cut into their practice?  And while he didn’t kill them on the spot, I guarantee he considered it.

Some company towns embraced hookworm eradication – they figured that outhouses and shoes were cheap, easily paid for by greater worker productivity. So various political types decided that he was a tool of the Interests, and therefore bad.

Somehow this idea reached the then-new Rockefeller foundation.  They did it right. They made sure that Charles Wardell Styles was not the public face of their effort – because he didn’t suffer fools gladly, and they needed someone who positively enjoyed them, someone who could get along with the general public. They went from town to town, rather like a revival, giving people fairly unpleasant chemicals that really did get rid of most of the hookworms. Since they are small( ~1 cm) and unspectacular, they kept dead giant roundworms (up to a foot long) in a bottle and pretended that they’d been expelled from the locals. They told people to use an outhouse and wear shoes – which led some  to claim that this was all an elaborate plot by John D. Rockefeller to sell shoes to innocent Southerners.  On the positive side, someone came up with the idea that the South would have won the War, except for hookworm : then worming folks was a tribute to the Lost Cause.

It worked.  Not perfectly, but well: greatly decreasing worm burden was good enough, since when it comes to hookworm, the dose makes the poison. A few may even be good for you, if you buy into the hygiene hypothesis.

There was another effect: it damaged the competitive position of black farmers.  They’re a good deal more resistant to hookworm (it came with them, probably), and hookworm resistance was likely one of the reasons for higher labor productivity among black farmers. Reducing and then eliminating malaria had the same effect.

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78 Responses to The Germ of Laziness

  1. “the dose makes the poison”. A concept slowly percolating into psychological models.

  2. dave chamberlin says:

    This is one of those Cochran pieces deserving of a trip over to Wikipedia to find out more. Wiki tells me that the predominate hookworm in the US requires a soil temperature above 18 degrees Celsius (that is 64 degrees Fahrenheit) and 40 inches of rain a year. So the deep south was a perfect breeding ground. A side effect of hookworm was diarrhea, just another case of parasitic cleverness, causing a side effect that helps it spread.

    The deep south was incredibly different not that long ago than it is today. I would visit my Texas cousins when air conditioning was a luxury most people could not afford and people moved and talked s-l-o-w. Push time back further than my lifetime and southerners moved far slower still because of the lazy germ and malaria.

    History is far more than emperors and empires, wars and turmoil. It is about a thousand ways life was radically different than it is today and the details of this are lost on almost everyone who is not curious. Oh well, their loss.

  3. The fourth doorman of the apocalypse says:

    The wearing of shoes (at least anong poor southern whites) might even become one of those little bits of culture that no one understands the reason for in the distant future when immigration has dumbed down the population.

    Possibly a bit like the prohibition of pork among some groups. Funny thing is, the Chinese seem to know how to cook pork such that those risks are reduced if not eliminated. It’s a conundrum of Gouldian proportions. Perhaps the SJ Gould of the 21st century, Carl Zimmer, is worthy of the task.

    • dearieme says:

      I’ve never seen the least evidence that the taboo against pork has anything to do with disease. I suspect it’s a bit like “popular etymology” – much repeated, but never backed up.

      • gcochran9 says:

        Trichinosis exists, but I doubt if abjuring pork net improves health.

        • karenjo12 says:

          There was a book published in 1987 called “Sacred Cow, Abominable Pig” which suggested that the reason for pork prohibition was because pigs can’t live in the dry, hot climate where Judaism and Islam grew up. Trichinosis was not a factor since almost any cooking technique kills the bugs.

          • The fourth doorman of the apocalypse says:

            Ummm, hello. They are prohibited because they can’t live there?

            Let me see, Durian is prohibited in MA because it doesn’t grow there. Yep, sounds like a good idea to me. Alligator meat is prohibited in Alaska because they can’t live there. By George, I think you are right.

        • johnb says:

          The author is Marvin Harris, the book is worth reading; its core is the application of ecological ideas (calories produced, seasonal stress, trade-offs) to human cultural practices.

          His idea about pigs was that while in northern Europe a pig is a way to turn inedible plant products (acorns, tubers) into tasty meat and thus a net win for all, in the Middle East a pig is a way to turn human-edible food into tasty meat and so there’s a trade-off: your village can have N people if it prohibits pigs or N-M people and M pigs if it allows pigs. Other things being equal, the villages with pig-prohibition will win conflicts with villages that don’t have pig-prohibition, so an initially rare meme (“tasty pigs are nonetheless forbidden by the gods”) will take over. It has to be a strong, i.e. religious, prohibition because the meat is so tasty and elites would otherwise cheat a bit.

      • The fourth doorman of the apocalypse says:

        Ahhh, so you think it is a cultural spandrel?

        • Patrick Boyle says:

          Not so much a spandrel as just a simple cultural practice. The Jews were a wandering people who kept and ate sheep and goats – animals that could travel with them. Pigs on the other hand were kept by settled peoples. Hate the towns people. Hate their animals.

          I read once in one of the ‘Sunday the Rabbi Slept Late’ mysteries the Rabbi explained that the Jews didn’t eat pigs because the only purpose for keeping pigs was consumption by humans and Jews were too moral to engage in such an immoral custom. How’s that for a self serving explanation?

      • Difference Maker says:

        I suspect it is combination of trichinosis, flu, and the loose hygiene of the animal

      • Greying Wanderer says:

        “I’ve never seen the least evidence that the taboo against pork has anything to do with disease.”

        It could have been wrongly connected to a disease like a Bronze Age “maisma” theory e.g. a group of nomadic sheep herders go to live near some settled pig herders, catch swine flu and blame it on eating the pigs rather than breathing their sneezes.

      • dave chamberlin says:

        Charles Mann in his book 1493 says pigs were to blame for spreading measles and small pox to the Amerinds. He says Hernando de Soto in his wanderings through Florida and the southeast back in 1539 brought pigs to North America which went feral becoming the ancestors of wild pigs known as razorbacks. He posits that these infected pigs really screwed over the Amerinds (kind of a pink omnivore conspiracy) so that very few Europeans ever laid eyes on the densely populated communities of Amerinds in the Southeast United States.

        The problem is I can’t find any confirmation that pigs are carriers of small pox at all and I can’t find any proof that pigs did any disease spreading to Amerinds except in Mann’s book. The usual blame for the spreading of disease in the Americas goes to African slaves that the Conquistadors took along which also smells kind of fishy to me. Why the Spanish couldn’t have been sick and infectious rather than pigs or slaves strikes me as unlikely, but what do i know.

        Charles Mann is a wonderful writer, the problem is you can’t trust him as a scholar. He sells the Americas as being densely populated in 1491 and because of those disease ridden feral pigs the Spanish let loose there is no written account of the densely populated North American Southeast. There is a big bickering match between the high counters and low counters of actual preColumbian populations in the America’s and Mann is a high counter. I don’t have a dog in this fight, but the more I learn, the less I trust the word of Charles Mann.

    • a very knowing American says:

      The Torah forbids consumption of the flesh of an ox which has killed a human being, which isn’t likely a matter of health.

      Food taboos are often about group identity — eg different Indian castes having different allowed foods. The taboo on pork might have started out as a pastoralist folk separating themselves from their settled neighbors, but Jewish kosher rules have come to be greatly intellectually elaborated. An organizing principle seems to be that in each of the three domains of land, water and air, certain animals are exemplary, by virtue of a proper diet (chewing cud, not eating flesh, etc.) and/or proper mode of locomotion (cloven hooves, swimming with fins, not crawling, etc.) and may be eaten by God’s exemplary people. Other animals are impure and suitable for the other nations. Other groups that have survived as religious minorities for a long time often have their own taboos. The actual content seems almost less important than the fact that it preserves a distinct identity.

      • Michael says:

        A good example of how this arises is seen in the Amish. They do lots of strange things, like not using buttons on their clothes. It isn’t because they think these things are bad, it’s because everyone else uses them, and they are using the taboo as a way to maintain their separation from the rest of society.

  4. Sean says:

    It would be interesting to know if the population of poor whites was greatly limited by hookworm and malaria. If they had a John Snow a couple of generations before and people paid attention to him, the South could have had, not just much more effective troops and a bigger economy, but a bigger army by the time of the Civil war .

    It is possible to see how genes conferring resistance to hookworm could have been heavily selected whereby African ancestry could have been selected for among poor whites in the south. Especially those using human excrement as manure (once a not uncommon practice in the south).

    “my Texas cousins when air conditioning was a luxury most people could not afford and people moved and talked s-l-o-w.”

    People from rural areas have brains less wired for fear and tend to be less anxious see here and ,a href=””>they walk slower.. They are closer to Aristotle’s “great-souled man”. The small farmer is the ideal citizen according to many pre modern theorists. Lawyers and actors talk slow, and in a deep voice, for added credibility.

  5. Sam says:

    By the way, the economist Hoyt Bleakley ( did some analysis of the economic impact of the hookworm eradication in the South a few years back. Not surprisingly, the eradication was associated with a significant positive effect on education and income in the region. Here is the article:

  6. Patrick Boyle says:

    My cousins in Maryland are my closest living relatives. They are both interested in genealogy. They tell me that we are descended from Abraham Piersay of Jamestown – the man who introduced black slaves into English speaking America.

    Piersay brought white bond servants with him from the slums of London to work in the fields. But the whites died too fast. They were in bond for seven years to pay for their passage, but few lived more than a year. The local Indians were also poor field hands. The colony was facing a crisis so Piersay was asked by the government to acquire some black slaves. He sailed off and found some Dutch slavers – and Bob’s your uncle.

    I imagine that Yellow Fever which the blacks brought with them was one factor that gave them a competitive advantage in the fields. I wonder if hookworm was another. I’m ordering a half dozen books from Amazon looking for answers. If this account is true I still don’t know what killed off the original white bondsmen before the black slaves came in 1619.

    Blacks with their Duffy genes are immune, I understand, to the Vivax plasmodium. Were the early white field hands dying from malaria? Something gave blacks a foothold in the New World. The original preference of the first colonists, it seems, was for poor whites to work the fields. They didn’t want to introduce blacks but it was that or starve. Any ideas?

    • The fourth doorman of the apocalypse says:

      Perhaps they should have thought of the Southern Chinese (who also have genetic adaptations for malaria …).

      • j says:

        You are not the first to have thought of that. Peru imported workers from all over the Pacific, and in the end they settled on Chinese coolies, as the most productive and manageable.

    • gcochran9 says:

      Probably dying from malaria. I’d guess occasional falciparum as well as vivax, considering the high death rate. Not yellow fever at first – that only reached the Americas in 1648. Hookworm may or may not have been around by then – I don’t know.

      Moving father north, or to higher altitude, largely eliminated the problem. On the other hand, the real money was in warm-weather crops with adjacent water transportation: malaria country.

    • athEIst says:

      I still don’t know what killed off the original white bondsmen before the black slaves came in 1619.
      Your ancestors, probably.

      • Sean says:

        You couldn’t breed white slaves, blacks could replenish themselves and multiply, that was an important difference. A white was born free. Early on they got around that by using indentured servant women and black men to make slave babies.

    • The fourth doorman of the apocalypse says:

      A History of Negro(sic) Slavery in New York:

      One of the paradoxes of life in the American colonies, where personal freedom and social mobility were so highly prized, is that most of the population was bound to some form of legal servitude. Bondage was the common lot of most of the early settler, for indentured servitude for whites and slavery for Negroes were integral parts of the colonial labor system.

      • dearieme says:

        I don’t see that as a “paradox”. You can argue (i) Seeing bondage would make the free settlers even keener on freedom, especially those who had earlier been indentured labour themselves, or (ii) The great model democracy, ancient Athens, was a slave society, as were the other Greek cities.

        Still, it allowed Dr Johnson one of his best sneers.

        • dearieme says:

          Herewith: “How is it that we hear the loudest yelps for liberty among the drivers of negroes?”

          • syon says:

            Good as polemic but not terribly accurate.The Revolution, after all, began in Massachusetts, where slavery was quite marginal .Plus, the abolition movement gained ground in the North during the revolt against the Crown:

            1777: Vermont abolishes slavery

            1780: Pennsylvania establishes a gradual emancipation act

            1781: Massachusetts ends slavery via the Quock Walker and Jennison Decisions.For the curious, here’s Chief Justice Cushing’s ruling:

            “As to the doctrine of slavery and the right of Christians to hold Africans in perpetual servitude, and sell and treat them as we do our horses and cattle, that (it is true) has been heretofore countenanced by the Province Laws formerly, but nowhere is it expressly enacted or established. It has been a usage — a usage which took its origin from the practice of some of the European nations, and the regulations of British government respecting the then Colonies, for the benefit of trade and wealth. But whatever sentiments have formerly prevailed in this particular or slid in upon us by the example of others, a different idea has taken place with the people of America, more favorable to the natural rights of mankind, and to that natural, innate desire of Liberty, with which Heaven (without regard to color, complexion, or shape of noses-features) has inspired all the human race. And upon this ground our Constitution of Government, by which the people of this Commonwealth have solemnly bound themselves, sets out with declaring that all men are born free and equal — and that every subject is entitled to liberty, and to have it guarded by the laws, as well as life and property — and in short is totally repugnant to the idea of being born slaves. This being the case, I think the idea of slavery is inconsistent with our own conduct and Constitution; and there can be no such thing as perpetual servitude of a rational creature, unless his liberty is forfeited by some criminal conduct or given up by personal consent or contract “

        • The fourth doorman of the apocalypse says:

          Are you not from the land of Shakespeare?

          The paradox is with the American myth of the land of the free being grounded in slavery and servitude.

          Of course, many forget that freedom is of little use to a hungry dying man.

      • syon says:

        Many problems with this, but two come rather readily to mind:

        1.Conflating indentured servitude with chattel slavery.

        2.Slaves, as a percentage of the population, varied from colony to colony.In Massachusetts, for example, they never amounted to more than 2% of the population.

  7. And slaves are more valued when one is talking about a cash crop (tobacco, rice to a lesser extent) versus mixed farming for survival.

    • Richard Sharpe says:

      Well, looking at that book linked above, indentured and/or involuntary labor seems to be very important during the early days of a colony. Perhaps in the future robots will be used instead.

  8. Steve Sailer says:

    There’s an obscure and puzzling old Twilight Zone episode that, as far as I can make out, is an extended metaphor about hookworm in the Old South.

    • The fourth doorman of the apocalypse says:

      Come on Steve, give it up! The name of the episode, that is!

      • Steve Sailer says:

        Well, nobody else according to Google thinks it’s a metaphor for the conquest of hookwork in the South, but that’s how it struck me:

        “In the 1962 entry “The Last Rites of Jeff Myrtlebank”, James Best stars in the title role as a hillbilly who rises up from his casket just in time before his inadvertent burial. The stunned doctor who pronounced him dead (Edgar Buchanan) is totally confounded by the occurrence and he’s not alone. The local townsfolk including Mr. Myrtlebank’s parents and his good-looking girlfriend Confort (Sherry Jackson) also believe that something supernatural has happened to him. “He just don’t have the same appetite he once had,” says his mother, played by Ezelle Poule. Even old Pa Myrtlebank (Ralph Moody) can’t understand why Jeff seems to have transformed into a workaholic since his return from the dead. Although never much of a fighter before, the newly-rejuvenated Myrtlebank has no trouble whipping the town bully. Finally the locals (led by veteran character actor Dub Taylor) decide to confront Myrtlebank and force him to leave the county. They’re more than convinced that he’s either possessed by the devil or a demon himself. Their actions are for naught, however, as Myrtlebank threatens them with a nasty variety of biblical plagues if they don’t treat him with respect. Knowing a winner when she sees one, Comfort immediately chooses to become Myrtlebank’s bride-to-be. Thereafter, the townsfolk decide to let the loving couple live in peace for the good of everyone—and especially themselves.”

  9. Gordo says:

    So what is the ‘hookworm’ of today Dr Cochran?

  10. The fourth doorman of the apocalypse says:

    Some might say that the inability or unwillingness to learn, say, Calculus, might be considered laziness.

    Those afflicted with hookworm might perhaps have an excuse, but what can we say about those who are afflicted with a genetic inability?

  11. athEIst says:

    but what can we say about those who are afflicted with a genetic inability?
    What we CAN say is nothing. You knew that.

  12. Greying Wanderer says:

    History is pretty interesting on its own (at least to me) but when you include this kind of thing it gets even more so.

  13. BB753 says:

    We are told that chlorovirus ATCV-1 makes us dumber. So does this nematode,Necator americanus, I presume (Hookworm). Toxoplasma gondii may make us crazy and make us like cats. On top of that, some unidentified virus may turn us gay. Any reason it has to be a virus, and not some bateria or even bigger bugs, like protozoa and nematodes?
    I also wonder if the wave of craziness and anomie that hit the West after WWI and WWII has to do with massive infections and poor sanitation during and after the wars. And shortly after WWII, Third World immigration. We do know that polio (enteroviruses) and tuberculosis are making a comeback.

  14. Campesino says:

    Many thanks for this post, which resurrects from history’s “memory hole” the role that hookworm as well as malaria and yellow fever played in the South well into the 20th century. And how they affected the culture and weighed on people’s minds.

    My family is from the South and my great-great grandfather, beginning in the 1880s, made a small fortune making and selling patent medicines (really ineffective “snake oil”) that were supposed to be effective in treating these diseases. He made a chill tonic that was supposed to protect from malaria and yellow fever and a liver tonic that was supposed to clean you out and deliver you from that dreaded lethargy. It’s amazing to read the liver tonic advertisements that describe the hookworm symptoms to a “T”.

    He used some of the money to build a mansion (1898) that is on the National Register of Historic Places. He died just after WWI but his sons kept the company going until after WWII. I actually was able to get a bottle of the chill tonic recently from a bottle collector.

    I also found posted on the internet a “cease and desist” order from the FDA, dating from the 1930s, that said the _____ Drug Company could no longer claim that its chill tonic could cure malaria.

  15. karch_buttreau says:

    I wonder if heriditary hemochromatosis (storage of too much iron) was originally an adaptation to hookworm.

  16. Jay1 says:

    O/T, but speaking of germs:
    “A genetic analysis of 409 pairs of gay twins has provided the strongest evidence yet that gay people are born gay. The study clearly links sexual orientation in men with two regions of the human genome that have been implicated before, one on the X chromosome and one on chromosome 8.”

    • gcochran9 says:

      There may well be weak genetic influences – there are on almost everything. But the heritability of homosexuality is low, identical twins are discordant 75% of the time, etc. Since MZ twins are that discordant, some environmental event has to matter.

      The results aren’t exactly strong: the X-chromosome locus doesn’t reach statistical significance, but it’s close, and another study fund a similar result. So maybe.

      Even weak genetic influences might tell you something interesting about etiology.

      • Toddy Cat says:

        There certainly do seem to be a lot of people trying very hard to find the “gay gene”. The intelligence gene? Maybe not so much, at least not in this country, at least not publically.

        • gcochran9 says:

          Actually, there’s more work – more solid too – on IQ genes. GWAS, which is to be preferred to linkage studies, and with very large samples.

          Right now, just about any conceivable explanation of homosexuality would be unacceptable in polite circles.

    • The fourth doorman of the apocalypse says:

      But surely those gay genes would have mutated!

    • Greying Wanderer says:

      If for the sake of argument the bug theory was correct then these results would imply those genes (Xq28 and 8q12) would somehow reduce resistance to it which might possibly provide clues to the identity of the bug.

    • erica says:

      Actually, the initial article was in error. The sample was of gay brothers, only some of whom were twins.

  17. Greying Wanderer says:

    semi-related random thought of the day

    If for the sake of argument eyes need a minimum amount of UV to stay healthy (but not too much) and that eye color effects this somehow then there ought to be a difference in some eyesight problems between people with blue or brown eyes in the US south and say Canada or possibly even better between blue and brown eyed people in Australia vs the same in Canada.

    That is do blue eyed people in Australia have more eyesight problems than blue eyed people in Canada and vice versa for brown-eyed?

    (This might also imply that brown-eyed people who wear sun glasses in strong sunlight regions might end up with eye problems as might blue-eyed people who didn’t.)


    If that was correct then it might explain lighter eyes among northern HGs (going back to brown eyes again in the icy north cos reflection) with only relatively minor skin lightening and the much lighter skin (cos diet) but still dark-eyed (cos strong sunlight region) adaptation of the farmers.

    With the combination of both (or all three if there was both a maritime and interior version of the HG adaptation) creating the final result.

    In that case it wouldn’t be the HG genes that cause paper-white people it would be the combined effect of the HG skin genes with the farmer skin genes.

    • Karl Zimmerman says:

      My understanding is that Europeans are more likely than Sub-Saharan Africans to get macular degeneration. Also, for the “dry” form, those with light eyes have higher risk than those with dark eyes. Of course, macular degeneration generally doesn’t happen until well after reproductive years, so it’s unlikely it had major selective pressure.

      Mild photophobia is more likely a reason for active selection. Light-eyed people have more issues filtering out bright sunlight, which means they have to squint more on sunny days. It’s pretty clear how this would directly cut into survival rates of hunter-gatherers, since temporary sun-blinding could make you less able to hunt, along with avoid being killed by predators or rivals.

  18. Richard Sharpe says:

    There was another effect: it damaged the competitive position of black farmers. They’re a good deal more resistant to hookworm (it came with them, probably), and hookworm resistance was likely one of the reasons for higher labor productivity among black farmers. Reducing and then eliminating malaria had the same effect.

    This surely has to be the very antithesis of the sort of gene X environment interactions that right thinking people keep telling us about.

  19. Pingback: Quick links (#20) | Urban Future (2.1)

  20. The fourth doorman of the apocalypse says:


    blockquote>As with many things, toxicity is in the dose.

    From: The Lotus Eaters by Tom Kratman. Published in 2010.

    You would want to start with the first in the series: A Desert Called Peace.

  21. The fourth doorman of the apocalypse says:

    An interesting claim embedded at this link:

    In the late ’90s, Michael Kremer, then an economics professor at MIT, was in Kenya working on an NGO project that distributed textbooks to schools in poor rural districts. Around that time, the ratio of children to textbooks in Kenya was 17 to 1. The intervention seemed obvious: Poor villages need textbooks, rich donors have the money to buy them. All we have to do is link them up.

    But in the early stages of the project, Kremer convinced the researchers to do it differently. He wanted to know whether giving kids textbooks actually made them better students. So instead of handing out books and making a simple before-and-after comparison, he designed the project like a pharmaceutical trial. He split the schools into groups, gave some of them the “treatment” (i.e., textbooks) and the others nothing. Then he tested everyone, not just the kids who got the books but also the kids who didn’t, to see if his intervention had any effect.

    It didn’t. The trial took four years, but it was conclusive: Some of the kids improved academically over that time and some got worse, but the treatment group wasn’t any better off than the control.

    Then Kremer tried something else. Maybe the kids weren’t struggling in school because of what was going on in the classroom, but because of what was going on outside of it. So again, Kremer split the schools into groups and spent three years testing and measuring them. This time, the treatment was an actual treatment—medication to eradicate stomach worms. Worm infections affect up to 600 million children around the world, sapping their nutrition and causing, among other things, anemia, stomachaches, and stunting.

    Once more, the results were conclusive: The deworming pills made the kids noticeably better off. Absence rates fell by 25 percent, the kids got taller, even their friends and families got healthier. By interrupting the chain of infection, the treatments had reduced worm infections in entire villages. Even more striking, when they tested the same kids nearly a decade later, they had more education and earned higher salaries. The female participants were less likely to be employed in domestic services.

    And compared with Kremer’s first trial, deworming was a bargain. Textbooks cost $2 to $3 each. Deworming pills were as little as 49 cents. When Kremer calculated the kids’ bump in lifetime wages compared with the cost of treatment, it was a 60-to-1 ratio.

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