New research indicates that the old debate over “nature vs. nurture” may be based in an incomplete understanding of how genetics and experience interact. Similarly to Danny Hillis’ remarks on the way that proteomics can help us create a new model of cancer, researchers at the Emory School of Medicine believe that epigenetics – the theory of genetic memory – may help us form a new model for stress-related disorders such as PTSD and generalized anxiety.
In this study, researchers exposed male rats to a scent, and combined that scent with unpleasant stimulus – thus teaching the animal to fear the scent. The researchers then looked at the rats’ offspring through several generations. Future generations, regardless of whether they had ever interacted with the rats who were originally exposed to the smell and stimulus, were fearful of that smell. Further testing found that genes responsible for creating sensitivity to that particular scent were activated in the sperm of the male rats exposed to the scent.
If it is true that our grandparents’ experiences impact our own reactions to stimuli, then much could be explained about cycles of abuse and trauma, obesity, and other behaviorally-related diseases in famliies.