For decades now, it’s been George Bonanno’s show-stopper in talks to scientific and lay audiences: a slide with four trajectories graphed on it, representing the psychological reactions of people subjected to the most potentially traumatic life events. One trajectory, labeled “chronic” and accounting for about 5-30 percent of people, starts high on the graph and stays there. A second, labeled “delayed,” accounting for from zero to 15 percent of people, initially starts somewhere near the middle, but goes up over time. A third, labeled “recovery” and accounting for 15 to 25 percent of people, starts high but makes its way downward in fits and starts. The fourth, labeled “resilience,” begins low, drops sharply and quickly levels out to near flatness — and that trajectory, which almost always elicits audience murmurs, represents the experience of approximately two thirds of people.

That slide, which Bonanno has confirmed in over 30 studies — including ones of people who were in close proximity to the 9/11 terrorist attack on the World Trade Center, of people left permanently paralyzed in accidents, and of soldiers who have seen the most brutal combat — distills the finding that has defined his career: Most people are resilient in the face of life’s most horrific events.

And yet, there are still skeptics.

“It doesn’t happen as often as it used to, but every now and then, someone will come up to me after I give a talk and say, ‘You know, you’re just wrong,’” says Bonanno, Professor of Clinical Psychology and Director of Teachers College’s Resilience Center for Veterans & Families. “And even among people who accept our findings intellectually, I think there’s a sense that this isn’t real, because it defies conventional trauma theory, which assumes that very few people could come through a major aversive event without showing at least some disturbance for a prolonged period.”

The headline here is that we are wired for resilience.

—George Bonanno, Professor of Clinical Psychology

Maybe now, though, the skeptics will be quieted. In a paper recently published in JAMA Psychiatry (part of the Journal of the American Medical Association), Bonanno and coauthors have definitively shown that there is a genetic basis for why people respond differently to potential trauma, and, in particular, for why, essentially, most people carry on after such experiences without missing more than a beat or two.

“The headline here is that we are wired for resilience,” says Bonanno.

[Read the full paper, “Discriminating Heterogeneous Trajectories of Resilience and Depression After Major Life Stressors Using Polygenic Scores,”  co-authored by: Bonanno’s former post-doctoral student Katharina Schultebraucks, Assistant Professor of Behavioral and Cognitive Sciences and Director of Computational Medicine and Artificial Intelligence at the Data Science Institute of Columbia University’s Vagelos College of Physicians and Surgeons; Karmel W. Choi, Clinical and Research Fellow in the Psychiatric & Neurodevelopmental Genetics Unit at Massachusetts General Hospital (MGH) and the Harvard T.H. Chan School of Public Health; and TC alumnus and former Bonanno student Isaac R. Galatzer-Levy (Ph.D. ’12), Chief Scientific Officer at AiCure and Adjunct Assistant Professor in the Department of Psychiatry at NYU Grossman School of Medicine.]

To conduct their research, Bonanno and coauthors tapped the Health and Retirement Study, which from 1992 through 2010 collected data every two years from U.S. citizens who were 50 or older. More specifically, they looked at the course of depression and resilience in older adults after a major life stressor, such as bereavement, divorce and job loss, or following major health events, such as heart attack or diagnosis of cancer.

The study used polygenic risk scores — a technique in which clusters of genes are assessed for how strongly they correlate with particular outcomes, such as, for example, depression, post-traumatic stress disorder, high cholesterol or successful educational attainment. But in the first work of its kind, Bonanno’s team built on those findings by assessing 5,000 participants in the study to see how strongly those same gene clusters predicted each of the four trajectories on Bonanno’s famous slide.

The findings mirrored the same conclusions Bonanno has reached in his previous, non-genetic outcomes studies. A “resilient” group, accounting for about two-thirds of all the participants studied, showed no depression before or after a potentially traumatic event.

Genetics is one piece of the puzzle. The resilience pattern is complicated — there are a lot of things that predict it, and none are exclusive...But what we’re talking about here is most people. Why are most people resilient while some aren’t? And now we know one very important reason, and in looking at a group, we can predict, with good accuracy, how many will turn out to be resilient.

—George Bonanno, Professor of Clinical Psychology

Bonanno is quick to point out that the association the study shows between genes and resilience outcomes is not determinative.

“Genetics is one piece of the puzzle,” he says. “The resilience pattern is complicated — there are a lot of things that predict it, and none are exclusive. You can have a genetic risk for a condition and you might never get it, and you might have no genetic risk profile and end up having a poor health outcome because of your lifestyle, because of stress, or possible changes in the parts of the gene that regulate other parts — known as epigenetics — which might lead people to react either too much or too little to stress.

“But what we’re talking about here is most people. Why are most people resilient while some aren’t? And now we know one very important reason, and in looking at a group, we can predict, with good accuracy, how many will turn out to be resilient.”

— Joe Levine