New research into the ways that humans develop phobias has come upon a surprising theory: It could be genetic. According to researchers at the Emory University School of Medicine, memories can be passed down between generations via genetic switches and chemical changes in DNA that make experiences a kind of inherited trait.
The study found that mice subjected to the smell of cherry blossom passed on a fear of the odor using shocks before they were allowed to mate. The offspring showed fear characteristics upon being subjected to cherry blossom despite never encountering it before. That generation of mice’s offspring displayed the same fear.
So the root of an irrational fear could be in something that happened to an ancestor. Per Dr. Brian Dias, from the department of psychiatry at Emory:
“From a translational perspective, 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.
“Such a phenomenon may contribute to the etiology and potential intergenerational transmission of risk for neuropsychiatric disorders such as phobias, anxiety and post-traumatic stress disorder.”
Next, the researchers will investigate how the fears become stored in DNA and test the theory that this is how humans pass on fears.