For Jews, the injunction to remember is deeply embedded in religious thought and practice, and in cultural life more generally. The Hebrew word transliterated as zakhor is the command “remember!” It is used frequently in the Hebrew Bible, as in the Commandments (zakhor et yom hashabbat lekadsho — remember the Sabbath day and sanctify it). As the late Rabbi Yosef Hayim Yerushalmi wrote in his 1982 essay Zakhor: Jewish History and Jewish Memory, the word
appears in its various declensions in the Bible no less than one hundred and sixty-nine times, usually with either Israel or God as the subject, for memory is incumbent upon both. The verb is complemented by its obverse — forgetting. As Israel is enjoined to remember, so it is adjured not to forget.
Yerushalmi’s book explores the dynamics of Jewish religious and cultural memory, from antiquity through our own times, and the complicated ways memory is in tension with the discipline of history. My colleagues at the American Association for the Advancement of Science’s Dialogue on Science, Ethics, and Religion (DOSER) have, in our project on “Science Engagement in Rabbinical Training,” explored Judaism and Jewish memory as one of our themes. How might modern scientific discoveries shape the Jewish understanding of memory?
Epigenetics and Memory
One relevant area of scientific research involves the Holocaust. For decades, researchers have studied the psychological and social effects of Holocaust trauma on subsequent generations. More recently, researchers have begun to explore how the trauma of the Holocaust can affect not only familial relationships, but also the very biology of survivors’ descendants.
A leading figure in this latter area of research is Rachel Yehuda, professor of psychiatry and neuroscience at the Icahn School of Medicine, and director of the school’s Traumatic Stress Studies Division. In a seminar cosponsored by AAAS/DOSER in January 2017, Yehuda discussed her research at the Rabbinical School of Hebrew College.
In 2007, Yehuda and colleagues published a paper that shows descendants of Holocaust survivors, like their parents, produce lower levels of the hormone cortisol — one of the symptoms of post-traumatic stress disorder. The causes of such biological changes in the offspring of Holocaust survivors seems difficult to reconcile with the dogma of genetic determinism, which holds that DNA controls our lives but is not in turn shaped by our experiences. But the new field of epigenetics — the study of heritable traits that cannot be explained by DNA alone — challenges that view, and provides a way to understand how our life experiences can shape our genes.
In a 2015 study, Yehuda and colleagues examined the epigenetics of Holocaust survivors and their children, and found that parents’ traumatic memories can modify the function of genes in the children of survivors. Yehuda’s team studied 32 men and women along with their adult children in “the first demonstration of an association of preconception parental trauma with epigenetic alterations that is evident in both exposed parent and offspring, providing potential insight into how severe psychophysiological trauma can have intergenerational effects.”
(It is worth noting that much of this research is still in its early stages, and that the studies published to date tend to have small sample sizes — in part because of the small number of Holocaust survivors alive today.)
All of these things combine together to determine whether or not what you’ve inherited — either genetically or epigenetically — becomes useful to you as a person. If the environment can transform you in one way, it can transform you in another way too. If we make little changes in very important circuits, this can have a very big impact on health and well-being.
Yehuda went on to discuss the implications of her findings for how we think about the relation between the generations more broadly:
There’s a quote in Ezekiel, “The fathers ate sour grapes, and the children’s teeth were set on edge.” So, the Jewish culture and religion has understood that children bear the burden of their parents’ legacy. Fair or unfair, it’s a fact. It’s a cultural fact. It’s a biological fact. Everyone is born with a unique set of genes. The task is to refine from these traits the best self that we can have and not get distracted by the traits that are weaker; build up the traits that are stronger. We all have the same job to do.
This is very different from saying that genes determine who we become, or even that genes and environment compete in some way to shape our futures. In a 2013 lecture sponsored by AAAS/DOSER, Denis Alexander, a molecular biologist and emeritus director of the Faraday Institute for Science and Religion, spoke to the issue of genetic determinism and the supposed dichotomy between nature and nurture; a reporter from AAAS paraphrased his remarks in this way: “Rather than focus on dueling forces, scientists should stress that human development is the product of complex, interwoven systems.”
Alexander mentioned a Finnish study that was misinterpreted by the media and the public to mean that we are entirely at the mercy of our genes. Researchers had found a particular mutation in 17 out of 228 violent criminals. But while over 100,000 people in Finland carry this mutation, only 3,500 of them were incarcerated at the time of the study. Thus, “the majority of people with this mutation are not violent offenders,” Alexander said. This is important because people could view themselves as puppets whose genes pull their strings. “Genes maybe influence us,” Alexander said, “but they certainly don’t control us, as if our genes and our genomes were somehow operating in a separate space from the rest of our personhood.”
The research into the epigenetic effects of Holocaust trauma might have practical consequences. Rabbi Dan Judson, director of professional development and placement at the Rabbinical School of Hebrew College, said the 2017 seminar at the Rabbinical School of Hebrew College was “a unique opportunity for students to learn from scientists who are working in fields which have a direct bearing on the work that rabbis do.” Yehuda’s presentation, Judson said, could shape the understanding of pastoral care. (And indeed, Yehuda herself is a coauthor of the 2016 book The Art of Jewish Pastoral Counseling: A Guide for All Faiths.) As Yehuda put it in her 2017 talk, “The effects of trauma are not only long-lasting, but transformative.” The question is: how do trauma survivors and their children ensure that the transformation is constructive rather than destructive?
Science and Religion in Dialogue
Beyond the epigenetic studies of a sort of “memory” inscribed in the very bodies of survivors and their descendants, how might science inform Jewish religious understanding and practice?
According to a 2014 study conducted by the AAAS in collaboration with sociologists at Rice University, almost a quarter of American Jews see religion and science as being in conflict. The vast majority of that group — that is, over 90 percent of the American Jews who see science and religion in conflict — said they see themselves on the side of science. Among all religious groups, Jews were both most likely to see science and religion as “independent” of one another and least likely to see science and religion as “collaborative.”
As Rabbi Geoffrey Mitelman, founding director of the science-and-Judaism initiative Sinai and Synapses, put it, “every other religious group was more likely to find that science could enhance their religious outlook than the Jewish community. Instead, Jews were much more likely to separate their religious and their scientific outlooks and keep them siloed off.”
At a 2014 workshop hosted by AAAS that brought together rabbis and scientists, a participant who wears both hats said, “My underlying conflict is that as a scientist I’m trained to look for answers; as a rabbi I’m taught to live with questions.”
Mitelman sees this compartmentalization as an opportunity. “If Jews tend to have a positive outlook on science, why not use science to help people enhance their connection to Judaism?”