Trans-generational Transmission of Trauma

We are shaped by the genes we inherit, but a new field of scientific study, Epigenetics, is revealing we pass down more than just our genetics.

According to the Center for Disease Control and Prevention (CDC), “Epigenetics is the study of how your behaviors and environment can cause changes that affect the way your genes work.” In other words, your experiences can shape your genes enough to pass those changes down to your children. This has far-flung social implications for those experiencing poverty, racism, abuse, homelessness, and other forms of systemic trauma.

Researchers are producing a steady stream of studies on animals and humans that replicate these findings. For example, one 2013 study conducted on mice found an intergenerational effect of trauma associated with scent. The researchers blew a cherry blossom scent through the cages of adult male mice while zapping their feet with an electric current. After several repetitions, the mice associated the smell with pain. Not long after, the males were bred. When their pups smelled that same cherry blossom scent (without being submitted to any pain), they experienced increased nervousness. They were jumpier than the pups of fathers who hadn’t gone through the experience. This behavior was repeated with the grandpups.

The experiment continued. Pups of traumatized fathers were then raised by unrelated mice who weren’t familiar with the cherry blossom scent to rule out the pups' learning behavior from their parents. This sensitivity to the smell was linked to epigenetic modifications through sperm DNA.

Now, here is the coolest part of this study: the same mice who were conditioned to fear the cherry blossom scent were later desensitized to the smell — in other words, their trauma was healed. Researchers found their sperm then lost the characteristic “fearful” epigenetic signature. The new pups of the desensitized males also no longer showed sensitivity to the scent.

How amazing is that? This is excellent news because, unlike genes, we can change or reverse epigenetics. While this is a young science and can be controversial at times, I believe it will shed insight into how the experiences of one generation can affect the next.

Comments (0)

Leave a comment