Can Your Grandparents' Trauma Make You More Anxious?

Do memories change DNA?. photo credit: ynse via photopin cc

The Holocaust. Slavery. The atomic bombing of Hiroshima and Nagasaki. Genocide. Few have a family history unscarred by trauma. But can these memories be passed down through generations? 

Research on Memory's Transmission

Research out of Emory University School of Medicine on mice demonstrates that memories can be inherited. Specifically, researchers trained mice to fear the smell of cherry blossoms.

They then found that there was a part of DNA in the mice's sperm that changed in a way that reflected a greater sensitivity to the smell of the cherry blossoms, and that this sensitivity was passed down to their offspring and their offspring's offspring, who also demonstrated high sensitivity to the smell of cherry blossoms despite never having encountered it before in their lifetimes. 

Possible Implications

Dr. Brian Dias of Emory University conceived the study and was one author. He indicates that "our results allow us to appreciate how the experiences of a parent, before even conceiving offspring, markedly influence both structure and function in the nervous system of subsequent generations." He notes that this research could point to further findings on the possible transmission of risk for anxiety disorders including phobias and Post-traumatic Stress Disorder. In other words, there is a possibility that if your ancestor experienced trauma, his or her DNA structure may have been altered to reflect that, and this could have been passed along.

Nature Versus Nurture

It is widely accepted that both nature, including heredity and genetics, and nurture, including life experiences, contribute to the etiology of psychiatric disorders. This study points to the possibility that life experiences can actually alter genetic code, causing offspring to inherit genetic sensitivities.

The reason why someone might be anxious may not just be because their parents happened to be extra nervous and so the anxiety was "learned" behavior, but may also be because there was a genetic change along the way. 

Future Research

Clearly, this research opens up a wide world of possibility around the biological transmission of memory and altered DNA from experiences, but it's important to remember that this research was specifically on the olfactory memory of mice. To generalize this to humans would be a stretch; more study is needed to see if a similar phenomenon happens in human DNA. 


Dias, BG & Ressler, KJ. Parental olfactory experience influences behavior and neural structure in subsequent generations. Nature Neuroscience.17, 89-96 (2014).

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