For better or worse—and despite resolutions to the contrary—we all end up like our parents to some extent. Over time, I’ve noticed my thinking has become strangely familiar, as though I’ve heard it somewhere before…and then I realize I just thought or said something my dad would say. Just the other day, I realized that I sign my name exactly like my mom does, even though as a kid I used to complain that she trails off after writing the “R” of our last name. Genes work strange magic sometimes, conflating nurture and nature and working far deeper than the conventional inheritance of diseases or other health conditions. Researchers now believe that symptoms of trauma, once thought to be non-genetic responses, can actually be passed down via sperm.
Scientists have always wondered why descendants of trauma survivors are more inclined toward mental illness than the average person. Some have looked to genetic to explain it, but have come up empty. A new study in Nature Neuroscience suggests that trauma in early life can affect a mechanism that dictates gene expression, in mouse sperm. Trauma changes gene expression, which then has cascading biological effects. But what wasn’t clear is whether those changes could be passed down to future generations. The provocative question raises the possibility of the inheritance of non-genetic traits.