A boy and his baby brother hide in a forest for months, sleeping in a hole dug underground. They must keep silent to avoid attracting the attention of the soldiers who have invaded their village; but one day, the baby starts crying and won’t stop. Terrified, the boy tries to hush his brother, holding him tight, but the baby cries and cries. The boy holds him tighter and tighter, desperately trying to make the baby stop crying, trying to save both their lives, but his brother won’t stop. Until suddenly he does. The little body goes still, and the baby never makes another sound.
A generation later, the boy has a daughter. She is very successful, known nationwide for her work. But she suffers from asthma and has trouble breathing, especially when she becomes panicked. She is deeply fearful of abandonment and death. One might wonder: Was her father’s trauma passed on to her, manifesting itself in her physiological and psychological issues?
Scientists and therapists are now trying to understand how trauma — broadly defined as severe psychological distress following a terrible or life-threatening event — is shared across generations, whether the connection is biological or psychological, and how best to stop the legacy of pain.
There is mounting evidence that the offspring of trauma survivors — of genocide, war, slavery, famine and other traumatic situations — have a greater risk of depression, anxiety, post-traumatic stress disorder, alcoholism, metabolic disorders, and even premature death. But the big question is whether these traits are the result of overhearing their traumatized parents’ stories and adopting their behaviors, or whether the trauma actually changed the parents’ genomes in such a way that the consequences were passed down to their offspring.
“The conundrum with a phenomenon like this is how much of it is biological inheritance—that is, sperm and egg—versus social transmission of information, which is akin to Grandma sitting at the dinner table and talking to you about the atrocities that she and her family might have experienced,” says Brian Dias, an…