The Invisible History of the Human Race

by Christine Kenneally

  Nunn and Wantchekon’s assertion that mistrust and silence could be passed down for more than a century was shocking. We don’t normally think of ideas and attitudes persisting for so long. Could they be passed down over even longer periods of time?

  • • •

  In 1348 in a castle on Lake Geneva, a Jewish man named Agimet was tortured “in the presence of a great many trustworthy persons.” Eventually he broke and confessed to having caused the Black Death by poisoning the local wells. In the previous year the plague had swept into Europe via the Silk Road. In village after village in Europe, people awoke to find themselves feverish, the skin of their fingers and toes turning black, and their lymph nodes swelling grotesquely until they split open and bled. Victims bled internally as well, urinating blood and coughing it up, until they died in great pain.

  The plague, which was highly contagious and destroyed entire families and villages, is believed to have killed as many as fifty million people in Europe (60 percent of the population) and seventy-five million worldwide. At the time, no one understood what the dread affliction was or where it came from. Some believed it must be a punishment from God, a consequence of the movement of the planets, or a malady created by humans. Many people blamed it on the Jews, the largest minority in Europe at the time, or on people with disabilities, and in some rare cases even on the nobility. Primarily, though, the Jews were held accountable, and after Agimet’s torture, terrible pogroms (violent riots that target a specific ethnic group) took place all over Europe for more than a decade.

  Out of 320 towns that had a Jewish community in the territory that later became Germany, 232 carried out pogroms, destroying homes, inflicting torture, and expelling or killing Jewish inhabitants. In many areas entire communities were disbanded, and fleeing Jews were set upon by peasant mobs. Seventy-nine towns remained peaceful. The Jews even had defenders among the Christians. Pope Clement VI declared that well poisoning was a crime “without plausibility.” Medical faculties in many towns also asserted that the stories about well poisoning were false. But reason had little effect on the panic. As the plague took hold in Basel, Switzerland, and more Christians died from the infection than Jews, on January 9, 1349, some six hundred Jews were forced into a specially constructed wooden building on an island in the Rhine, where they were burned alive.

  After three years the worst of the plague was over, but the fear and the hatred it engendered persisted. In one of the most remarkable studies of the transmission of ideas over time, the economists Nico Voigtländer and Hans-Joachim Voth found evidence that animosity endured generation after generation, for as long as six hundred years.

  Voigtländer and Voth compared the treatment of Jewish people in towns after the Black Death with their treatment in the same towns in the 1920s. Following World War I, anti-Semitism was on the rise in Germany. Many Germans blamed Jews for the war, and once again villagers turned on their own neighbors, carrying out pogroms. The researchers identified the towns that exhibited the most virulent anti-Semitism in pre–World War II Germany, and they found a remarkable correlation with the Black Death pogroms. Of the twenty pogroms that took place in the 1920s, Voigtländer and Voth found that nineteen were carried out in towns that had also attacked their Jewish communities in the fourteenth century. If you were a Jew in 1920s Germany and you lived in a town where no medieval pogroms took place, your chance of being attacked by your fellow townsfolk was 1.1 percent. But if you were Jewish and you lived in a town where a medieval pogrom had occurred, the chance that you would be attacked rose to 8.2 percent.

  The researchers compared the cities of Aachen and Würzburg, which were similar in size before World War II. Jews had lived in Würzburg since 1100, while Aachen had had a Jewish community since 1242. There is no record of any violence against Jews in Aachen before or during the Black Death. By contrast, the citizens of Würzburg turned on their Jewish community and killed eight hundred people. Voigtländer and Voth noted the sentiments of medieval Würzburg’s notary, who wrote to his bishop, “The Jews deserved to be swallowed up in flames.” Over six hundred years later, even though both communities destroyed their Jewish synagogues, only Würzburg had pogroms.

  • • •

  Voigtländer and Voth didn’t only examine direct violence against Jews in 1920s Germany; they tracked anti-Semitism in a number of ways. One measure was the poll performance of the Nazi Party in 1928, when the Nazis did not yet have mass popularity. “In places with a history of Jew-burning,” wrote Voigtländer and Voth, “the Nazi Party received 1.5 times as many votes as in places without it.”

  Letters to the editor of Der Stürmer, a particularly racist Nazi newspaper, also showed a link with the very distant past. The researchers determined the location of writers of this correspondence and found a strong link with towns that had carried out medieval attacks on Jews. In the 1920s residents of Würzburg wrote ten times as many anti-Semitic letters to the editor as did residents of other towns.

  “Dear Stürmer,” wrote one schoolgirl. “Regrettably, [the students in my school] still have many Jewish fellow students. Equally regrettably, many German girls are still close friends with these Jewish girls. . . . I consider these friendships very dangerous since the Jews and their corrupting ideas destroy the souls of the girls slowly but surely.”

  After 1939 more Jews were deported to camps from areas that had a history of medieval violence than from areas that did not. Even though deportation during this period was a national policy, Voigtländer and Voth argue that rules were enforced by local authority: The numbers of Jews who were deported reflected how stringently local administrators judged their citizens’ proof of ancestry. Eric Ehrenreich came to the same conclusion when he examined genealogy and ancestral proof. Even during Kristallnacht, when all across Germany the hateful treatment of Jewish people was effectively licensed by the Nazi Party, more Jewish synagogues were attacked in towns where Jews had been killed six hundred years earlier than in towns where they hadn’t.

  Voigtländer and Voth are not suggesting that relationships among different cultures in Europe were always harmonious before the Black Death. In fact, pogroms took place before the 1300s. (In England, where there were no pogroms following the Black Death, that was due not to the absence of hatred so much as to the fact that the English had already expelled their Jewish population in 1290). Still, many more pogroms occurred in Europe after the Black Death hit.

  The details of medieval pogroms and twentieth-century anti-Semitic attacks have been known for a long time, but until Voigtländer and Voth’s analysis, no one had tried to determine whether the two might be connected. Partly this is because no one had imagined that attitudes could endure for so long.

  If the connection between hateful acts across the centuries and between trauma and distrust over generational time is real, how do the ideas and the feelings persist? How might they be passed down from one generation to the next? Can the personal qualities of a great-great-great-grandfather, like his faith in people or his suspicion of them, really influence the feelings of his descendants today?

  • • •

  I asked Voigtländer how such hatred was preserved over the course of centuries. He and Voth found that in cities that grew significantly after 1750, the long-term transmission of anti-Semitism was disrupted. Crucially, these rapidly industrializing cities expanded because many people moved in from elsewhere, not because the locals had more children. Where Jew-hatred persisted, there were relatively fewer people coming in. “Even though migration everywhere increased rapidly after 1820, most inhabitants of a typical town in our sample must have been direct descendants of those who lived there in 1350,” they wrote.

  Nunn also wondered about who was passing down the distrust in Africa. There was no way to track it through time beyond the records that he and Wantchekon had already examined. There was also no literature that surveyed trust in earlier periods, no handy Afrobarometer that logged attitu
des in different families and communities over time.

  So Nunn and Wantchekon estimated for each individual whose trust was surveyed how many slaves were taken from his personal ethnic group and how many slaves were taken from the areas where he lived. The underlying idea was that, if you are taught values primarily by your family, you are likely to take those with you wherever you go. But if you absorb values from the people who live around you and from the legal, social, and political institutions in a particular region, then where you live may have more impact on your beliefs than what you learned from your parents. If this was the case, then when someone left his native village and moved to a place with a different predominant attitude, he might modify his existing values by virtue of being surrounded by people with different ones. Similarly, if someone moved into a region where all the civic organizations seemed to foster distrust, then even if he came from a previously trusting place, he might take up the local culture and become less trusting himself.

  It seemed that both families and social institutions matter but that the former is more powerful. The data suggested that a region might develop its own culture of distrust and that it could affect people who moved into that area, even if their ancestors had not been exposed to the historical event that destroyed trust in the first place. But if someone’s ancestors had significant exposure to the slave trade, then even if he moved away from the area where he was born to an area where there was no general culture of mistrust, he was still less likely to be trusting. Indeed, Nunn and Wantchekon found evidence that the inheritance of distrust within a family was twice as powerful as the distrust that is passed down in a community.

  This accords well with our personal intuitions about families: The people who raise us shape us, intentionally or unintentionally. The people who raise us were likewise shaped by the people who raised them, and so on. Similarly, the way we treat other people, even our offspring, is shaped by the way we were shaped. This is not to say that our peers don’t affect our attitudes, nor does it mean that the society in which we choose to live doesn’t contribute as well. Obviously, the older we get, the more we develop the ability to shape ourselves. Family history doesn’t necessarily determine who we become, but this body of work suggests that the effect of a family may be so powerful that it can be replicated down through many generations, over and over through hundreds of years. It’s no wonder that so many people choose to study the distant histories of their families to understand how they work today. If genealogists believe there isn’t enough in their daily lives or their culture that sufficiently explains who they are—either to others or to themselves—it may be because they are right.

  In fact, the legacy of a family may be so powerful that it will not only last over extraordinary periods of time but extend over great distances as well.

  • • •

  Catastrophic events like the plague or slavery are not the only ones that echo down the generations. Widespread and deeply held beliefs can be traced to apparently benign events too, like the invention of technology. In the 1970s the Danish economist Ester Boserup argued that the invention of the plow transformed the way men and women viewed themselves. Boserup’s idea was that because the device changed how farming communities labored, it also changed how people thought about labor itself and about who should be responsible for it.

  The main farming technology that existed when the plow was introduced was shifting cultivation. Using a plow takes a lot of upper-body strength and manual power, whereas shifting cultivation relies on handheld tools like hoes and does not require as much strength. As communities took up the plow, it was most effectively used by stronger individuals, and these were most often men. In societies that used shifting cultivation, both men and women used the technology. Of course, the plow was invented not to exclude women but to make cultivation faster and easier in areas where crops like wheat, barley, and teff were grown over large, flat tracts of land in deep soil. Communities living where sorghum and millet grew best—typically in rocky soil—continued to use the hoe. Boserup believed that after the plow forced specialization of labor, with men in the field and women remaining in the home, people formed the belief—after the fact—that this arrangement was how it should be and that women were best suited to home life.

  Boserup made a solid historical argument, but no one had tried to measure whether beliefs about innate differences between men and women across the world could really be mapped according to whether their ancestors had used the plow. Nathan Nunn read Boserup’s ideas in graduate school, and ten years later he and some colleagues decided to test them.

  Once again Nunn searched for ways to measure the Old World against the new. He and his colleagues divided societies up according to whether they used the plow or shifting cultivation. They gathered current data about male and female lives, including how much women in different societies worked in public versus how much they worked in the home, how often they owned companies, and the degree to which they participated in politics. They also measured public attitudes by comparing responses to statements in the World Value Survey like “When jobs are scarce, men should have more right to a job than a woman.”

  Nunn found that if you asked an individual whose ancestors grew wheat about his beliefs regarding women’s place, it was much more likely that his notion of gender equality would be weaker than that of someone whose ancestors had grown sorghum or millet. Where the plow was used there was greater gender inequality and women were less common in the workforce. This was true even in contemporary societies in which most of the subjects would never even have seen a plow, much less used one, and in societies where plows today are fully mechanized to the point that a child of either gender would be capable of operating one.

  Similar research in the cultural inheritance of psychology has explored the difference between cultures in the West and the East. Many studies have found evidence for more individualistic, analytic ways of thought in the West and more interdependent and holistic conceptions of the self and cooperation in the East. But in 2014 a team of psychologists investigated these differences in populations within China based on whether the culture in question traditionally grew wheat or rice. Comparing cultures within China rather than between the East and West enabled the researchers to remove many confounding factors, like religion and language.

  Participants underwent a series of tests in which they paired two of three pictures. In previous studies the way a dog, a rabbit, and a carrot were paired differed according to whether the subject was from the West or the East. The Eastern subjects tended to pair the rabbit with a carrot, which was thought to be the more holistic, relational solution. The Western subjects paired the dog and the rabbit, which is more analytic because the animals belong in the same category. In another test subjects drew pictures of themselves and their friends. Previous studies had shown that westerners drew themselves larger than their friends. Another test surveyed how likely people were to privilege friends over strangers; typically Eastern cultures score higher on this measure.

  In all the tests the researchers found that, independent of a community’s wealth or its exposure to pathogens or to other cultures, the people whose ancestors grew rice were much more relational in their thinking than the people whose ancestors were wheat growers. Other measures pointed at differences between the two groups. For example, people from a wheat-growing culture divorced significantly more often than people from a rice-growing culture, a pattern that echoes the difference in divorce rates between the West and the East. The findings were true for people who live in rice and wheat communities today regardless of their occupation; even when subjects had nothing to do with the production of crops, they still inherited the cultural predispositions of their farming forebears.

  The differences between the cultures are attributed to the different demands of the two kinds of agriculture. Rice farming depends on complicated irrigation and the cooperation of farmers around the use of water. It als
o requires twice the amount of labor that is necessary for wheat, so rice-growing communities often stagger the planting of crops in order that all their members can help with the harvest. Wheat farming, by contrast, doesn’t need complicated irrigation or systems of cooperation among growers.

  The implication of these studies is that the way we see the world and act in it—whether the end result is gender inequality or trusting strangers—is significantly shaped by internal beliefs and norms that have been passed down in families and small communities. It seems that these norms are even taken with an individual when he moves to another country. But how might history have such a powerful impact on families, even when they have moved away from the place where that history, whatever it was, took place?

  • • •

  How do immigrants reproduce old values once they have left behind the old institutions and local beliefs that reinforced them? Raquel Fernandez and Alessandra Fogli wondered if second-generation daughters of immigrants to the United States might still be affected by the values of their parents’ home countries, even if the women themselves had never been there. Their subject group was women in the 1970s who were born in the States but whose parents came from elsewhere, and they asked specifically how much they worked and how many children they had.

  If the contemporary U.S. society in which the women grew up had the biggest effect on their lives, argued Fernandez and Fogli, then their work and family profiles should resemble those of their American peers who were not children of immigrants. If the culture of the family was a more significant factor, then women’s choices would look more like those of their grandparents’ generation. The researchers compared data about work and children in the 1970 U.S. census with data from each woman’s parents’ country of origin in the 1950s. They found that even when the present mattered, the past still had significant influence. If the 1950 data revealed that women in the parents’ country of origin worked more, then the U.S.-born daughter worked on average a week more every year. If the 1950s data showed that women in the parents’ country of origin had more children, then the U.S.-born daughter had more children than her peers who were not second-generation immigrants.