Judith Shulevitz explores the growing evidence that trauma can be inherited – yes, biologically. The controversial implications:
At the frontier of this research lies a very delicate question: whether some people, and some populations, are simply more susceptible to damage than others. We think of resilience to adversity as a function of character or culture. But as researchers unravel the biology of trauma, the more it seems that some people are likelier to be broken by calamity while others are likelier to endure it.
For instance, studies comparing twins in which one twin developed PTSD after trauma, and the other never had the bad experience and therefore never received the diagnosis, have uncovered shared brain structures that predispose them to traumatization.
These architectural anomalies include smaller hippocampuses—which reduce the brain’s ability to manage the neurological and hormonal components of fear—and an abnormal cavity holding apart two leaves of a membrane in the center of the brain, an aberration that has been linked to schizophrenia, among other disorders. Researchers have further identified genetic variations that seem to magnify the impact of trauma. One study on the mutations of a certain gene found that a particular variation had more of an “orchid” effect on African Americans than on Americans of European descent. The African Americans were more susceptible than the European Americans to PTSD if abused as children and less susceptible if not.
Another theory, even more uncomfortable to consider, holds that a particular parental dowry may drive a person to put herself in situations in which she is more likely to be hurt. Neuropsychologists have identified heritable traits that push people toward risk: attention deficits, a difficulty articulating one’s memories, low executive function or self-control. The “high-risk hypothesis,” as it is known, sounds a lot like blaming the victim. But it isn’t all that different from saying that people have different personalities and interact with the world in different ways. As Yehuda puts it, “Biology may help us understand things in a way that we’re afraid to say or that we can’t say.”