Scientific Evidence for Generational Wounds

Virginia

A Discover Magazine article caught my attention this week. It’s entitled “Grandma’s Experiences Leave a Mark on Your Genes” by Dan Hurly (July/Aug 2013.) Despite certain journalistic shortcomings, (an unclear chronology of events and some unchecked androcentrism,) I found the article noteworthy and thought you might too, for it cites experimental evidence that emotional wounds can be passed down for generations.

For many, the reality of generational wounding is clearly observable and experientially obvious. We internalize our parent’s wounds and also form identities in relation to their wounds, and they did the same with their parents, and so on. For some, however, proof of generational wounding is an epiphany, which means it has the potential, if it becomes common knowledge, to contribute to the emergence of a more conscious, compassionate humanity.

The subtitle of Hurly’s article reads, “Your ancestors’ lousy childhoods or excellent adventures might change your personality, bequeathing anxiety or resilience by altering the epigenetic expressions of genes in the brain.” Epi is Greek for “over,” “above,” or “outer,” so epigenetic refers to “alterations in gene expression that are caused by mechanisms other than changes in the DNA sequence” (Shilatifard). Behavioral epigenetics, then, refers to the study of alterations in gene expression that are caused by behavioral influences, like nurturing, neglect, or physical abuse. This recent field of study logically emerged from the discovery of methylation and its effects on gene expression. Methylation is the addition of a methyl group to a molecule – an epigenetic mechanism that locks genes in the “off” position. Hurly creatively compared it to “a placeholder in a cookbook” as well as “molecular bric-a-brac.”

Much of the research focused on methylation has been conducted by cancer researchers who concluded that certain dietary habits and exposure to chemicals can turn off tumor suppressor genes, (Philips). But it was biologist Randy Jirtl who discovered that the addition or subtraction of methyl groups could be inherited. Add this knowledge to the scientific drive to understand the exact mechanism by which maternal care effects an offspring’s ability to handle stress, and we have the fledgling field of behavioral epigenetics – a science that was birthed over beers in a bar and an excited conversation between between two newly introduced specialists –  neurobiologist Michael Meaney and molecular biologist/geneticist Moshe Szyf.

Meaney and Szyf met in 1992 at a bar in Madrid where Meaney proposed to Szyf that maternal care could cause epigenetic changes to the brain, a hypothesis that Hurly considers “as improbable as it was profound.” Though Szyf was already considered an expert in the field of epigenetic mechanics, it had never occurred to him that changes could occur “simply due to maternal care.” Hurly quotes him as saying,

“It sounded like voodoo at first. For a molecular biologist, anything that didn’t have a clear molecular pathway was not serious science. But the longer we talked, the more I realized that maternal care just might be capable of causing changes in DNA methylation, as crazy as that sounded. So Michael and I decided we’d have to do the experiment to find out.”

(Warning: Animal experimentation is about to be described. If you would prefer, please skip to the implications.)

As it turned out, Meaney and Szyf’s fateful meeting led to not one but a series of experiments with rats. First they proved that rats who were raised by highly attentive mothers rarely had methylated glucocorticoid receptors, which meant that their brains could effectively manage stress responses. Conversely, rats who were raised by inattentive mothers had highly methylated glucocorticoid receptors and responded to stress poorly.

Next they demonstrated that the behavioral effects were solely due to the maternal care. They did this by switching rats who had inattentive mothers with those who had attentive ones, and sure enough the quality of nurturing reversed the methylation as well as its behavioral effects.

To bolster their findings, Meaney and Szyf took another group of rats who were damaged by inattentive mothering and “infused their brains with trictostatin A, a drug that can remove methyl groups.” These rats showed no behavioral issues, thus demonstrating that the behavioral effects were definitely related to the methylation. (And yes, there’s a drug that can remove methyl groups!)

This last bit of evidence gave our duo the confidence to share their news with their colleagues, but when the results of their experiments were submitted for publication one reviewer of a top science magazine staunchly refused to believe their findings. (How reactionary. Inattentive mothering, perhaps?) But Meaney and Szyf persevered and found a supporter at Nature Neuroscience. Their article, “Epigenetic Programming by Maternal Behavior,” was published in June 2004.

Next, Meaney and Szyf made the obvious move. They turned their attention to human subjects where they found a greater methylation of genes in the brains of individuals who committed suicide than those of individuals who died suddenly by factors other than suicide. Then Szyf went solo and found a greater methylation in the the genes of orphans than those of children raised by their biological parents.

And now we get to the evidence for more extended generational wounding. In a further study, Frances Champagne, a graduate student in Meaney’s lab, discovered that inattentive mothering caused methylation of the genes for estrogen receptors in the brains of their offspring. The resulting lack of estrogen receptors in the second generation of rats made them also less attentive to their offspring. Conclusions: negligence can be passed down for generations AND attentive mothering is important for the developing brain.

The question still remains, however, as to whether methylation is transferred directly to the zygote or is the result of negative behavioral influences. Further experiments involving bullied mice seem to point to the behavioral influences. Regardless, the importance of the research to date still stands. Hurly sums it up quite well when he writes,

“According to the new insights of behavioral epigenetics, traumatic experiences in our past, or in our recent ancestors’ past, leave molecular scars adhering to our DNA. Jews whose great-grandparents were chased from their Russian shtetls; Chinese whose grandparents lived through the ravages of the Cultural Revolution; young immigrants from Africa whose parents survived massacres; adults of every ethnicity who grew up with alcoholic or abusive parents — all carry with them more than just memories. Like silt deposited on the cogs of a finely tuned machine after the seawater of a tsunami recedes, our experiences and those of our forebears are never gone, even if they have been forgotten. They become a part of us, a molecular residue holding fast to our genetic scaffolding. The DNA remains the same, but psychological and behavioral tendencies are inherited.”

Implications

As an alternative therapist who tracks wounded identities back to their source in the past, often for several generations or more, I love that this paragraph speaks to the depth and breadth of human suffering. I will argue, however, with the assumption that methylation resulting from neglect and other forms of trauma is “never gone.” Hurly is paid to write compelling articles, (and he obviously isn’t given a lot of time to spend on them.) I imagine he was just thinking in metaphor and got caught up in the mood of a beautiful sentence. Regardless, he fails to mention, or either is simply not aware of, all the healing that has been facilitated and experienced by people who set their hearts and minds to it: shamanic healing, transformational bodywork, vipassana retreats, psychotropic journeys, experiential education, ceremony, prayer, life coaching, deep inner process work! All of these paths to healing, and more, have provided countless individuals with powerful transformative experiences and lasting positive behavioral changes. Surely it’s logical to hypothesize that these experiences could be erasing methylation.

Perhaps some day this hypothesis will be tested, but at the moment pharmaceutical companies are searching for epigenetic compounds to do the job –  pharmaceutical drugs to erase the methylation that causes depression, anxiety, and post-traumatic stress disorder in humans. At this prospect, Hurly wisely asks, “How could we be sure that epigenetic drugs would scrub clean only the dangerous marks, leaving beneficial – perhaps essential – methyl groups intact?” A very good question, and one that evokes images of Mrs. Hurdicure from the astoundingly perfect dark comedy Brain Candy. If you haven’t seen this film by Canadian sketch comedy troupe Kids in the Hall, be sure to do so before volunteering to be a test subject!

This prospect also begs the question, what would humanity be like if we could each simply take a drug to heal trauma? If we could really get a quick fix? Or more likely, what would the world be like it those who could afford it could get the quick fix? It takes courage and honesty to face and heal the pain of the past, and the insights gained are hard won and priceless. We grow from the self-reflection that healing from trauma requires. What would we become without it?

Overall, I appreciated Hurly’s article, but I just can’t let him slide when it comes to the comments that he made and quoted expressing astonishment at the idea that maternal care “just might be capable“ of effecting gene expression. The hypothesis was “as improbable as it was profound.” It “sounded like voodoo…,”  and even sounded “crazy.” Even though Hurly wrote later in his article, “the message that a mother’s love can make all the difference in a child’s life is nothing new,” he wasn’t aware of how derogatory his earlier language was with regard to the impact of nurturing.

Androcentrism, as you may know, is a perspective, often a condescending stance, “dominated by or emphasizing masculine interests or a masculine point of view” (Merriam Webster). For me, the language Hurly included in his article reflects that stance. It unintentionally belittles the contribution that nurturing makes to humanity.

If we trace it back, androcentrism is understandable. For millennia, most young males have been taught, (by both males and females,) that “big boys don’t cry,” and for millennia countless men and boys have had to suppress their emotions to defend their lives, homes, and families. It’s a common understanding that men have historically been raised to be less aware of their emotions, and still are in many homes, communities, and regions of the world. I see that lack of awareness of the emotions as a literal separation in consciousness – as a self-inflicted, internal wound created by the historical male’s need to impose traditional gender roles onto himself. But that wound was also inflicted externally, for men who had to negate their own feminine side to be the protector would also tend to project that negation outwards.

The separation was taken further, however, by the disenchanted world view created by the Scientific Revolution. Empiricism is the  claim that “sense experience is the ultimate source of all our concepts and knowledge” (Stanford Encyclopedia of Philosophy). Taken to its extreme, this perspective negates whatever which can’t be proven by science. It’s the perspective of some of the aforementioned males who were privileged enough to develop their intellects through education, particularly science, but who weren’t developing their emotional intelligence simultaneously. It’s the perspective of a separation marked by gender as well as class. So, despite their scientific rigor, or rather because of it, the perspective of many of these males became uniquely limited. It became exceptionally one-dimensional.

Virginia Woolf is known for once quipping, “Science, it would seem, is not sexless: he is a man, a father, and infected, too.” That comment was made in the 1930s, and though the scientific community now includes many women, and though much progress has been made with regard to healing the generational wounds caused by traditional gender roles, the androcentric stance is still subtly, if not blatantly, pervasive, depending on many factors that come to mind including one’s generational wounds. This article contains a subtle stance – seemingly innocuous, enthusiastic comments that negate the contribution of generations of women who made great personal sacrifices to bear and raise children. Language, both the spoken word and body language, can be incredibly insidious, unconsciously perpetuating inequalities that one believes he or she has out grown. I believe that it’s important to gently check androcentrism when we notice it, in others or in ourselves, and I hope I have been successful in conveying that spirit in this article.

I also hope that the understanding of generational wounding can contribute to a more conscious humanity, one that…

1. acknowledges the potential depth of the healing process and so has patience with it,

2. looks deeply for the source of external conflict and suffering,

3. and has a deeper understanding of the possible long-term effects of child care.

To conclude, I’ll give a plug to Conrad Hal Waddington, the scientist who coined the tern epigenetics in 1942, though at the time it referred to a field of study that would eventually be  called developmental biology. A quick google search into the history of epigentics led me to an article by D. Haig where I learned about Waddington. An integrative visionary, he declared the Neo-Darwinist view of his time that saw only “a simple correspondence between genes and characters as “extremist.” Instead, Waddington championed the idea that “the course of development was determined by the interactions of many genes with each other and with the environment.” For Waddington, Neo-Darwinism involved a “a breach between organism and nature as complete as the Cartesian dualism of mind and matter,” and he hoped that “an epigenetic consideration of evolution would go some way toward healing it.'”

Thank you, Conrad Hal Waddington. You were right. Your vision has even led to the discovery of scientific evidence of generational wounds, and I hope that your lineage of thought continues to lead us to a deeper and broader understanding of our multidimensional, interdependent composition.

References

Haig, D. (2004). Re: The Dual Origin of Epigenetics, Re: http://oeb.harvard.edu/faculty/haig/publication…/04epigeneticorigins.pdf

Hurly, Dan. (May 2013 issue). Re: Grandma’s Experience Leaves a Mark on Your Genes. Retrieved from http://discovermagazine.com/2013/may/13-grandmas-experiences-leave-epigenetic-mark-on-your-genes#.UfC6ErGgTMA

Philips, Theresa. (2008). Re: The Role of Methylation in Gene Expression. Retrieved from http://www.nature.com/scitable/topicpage/the-role-of-methylation-in-gene-expression-1070

Shilatifard, Ali. (April, 2009). Re: Definition of ‘Epigenetics’ Clarified. Retrieved from http://www.sciencedaily.com/releases/2009/04/090401181447.htm

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