Of Replication and Psychological Resilience: How Resilient Are Human Beings?

How resilient are people to the loss of a loved one, a natural disaster, a terrorist attack, or some other dreaded experience? The question is obviously an important one, and for a long time, it was assumed the answer was: not very. Partly because clinical populations predominated in early research, it appeared that most people took a long time to get over significant adversity. We now know that is not true. We know it on the basis of a substantial literature examining the aftermath of many aversive events (from terrorist attacks, military deployment, and mass shootings to bereavement, breast cancer surgery, traumatic injury, and heart attack).

Most people get through these experiences. They may experience some initial relatively short-lived distress, but they return to their previous functioning pretty soon after, remain able to experience positive emotions, and retain the capacity for generative experiences. More than anyone else, George Bonanno, a professor at Teachers College Columbia University, has outlined these capacities in an extensive and highly-cited body of work. He has overturned a number of wrong-headed assumptions about people’s vulnerability to potentially traumatizing experiences and the ways we cope with them.

How Common is Resilience?

Nevertheless, a recent paper takes square aim at Bonanno’s work by seeking to “replicate” two recent papers demonstrating the prevalence of resilient outcomes. (Full disclosure: I am a longtime friend and collaborator of Bonanno’s, the first author on one paper, and the third author on the other. He had no part in writing this blog post.)

Published in Perspectives in Psych Science, this recent paper—by Frank Infurna, an assistant professor at Arizona State, and Suniya Luthar, also a professor at Arizona State and a well-known scholar of childhood resilience—is entitled: “Resilience to Major Life Stressors is Not as Common as Was Thought” (Infurna & Luthar, 2016). As it suggests, they maintain that previous estimates of resilience (and the entire resilience literature) are wrong.

Are they right?

Replicating Previous Work on Resilience

First, some backstory. A firestorm has been raging over psychologists’ routine research practices, leading to the concern that many published research findings are actually false. The match that lit this firestorm was Daryl Bem’s now famous (or infamous) paper on ESP, and the gasoline that turned it into a five-alarm warehouse fire was a large-scale effort to systematically replicate 100 findings in well-known journals. The sobering results (only 38% clearly replicated) made the front page of The New York Times—no mean feat—and went on to generate controversies of its own. See here and here for debate regarding the conclusions of that study.

As these issues were thrust to the fore, replication became a cause célèbre, making research superstars out of its proponents and fueling movements toward openness and transparency in science more broadly. Few would question that these developments were overdue and salutary for psychological science. Nevertheless, in this context, Infurna and Luthar’s paper had particular pop and sizzle.

Indeed, their first sentence seizes the replication zeitgeist by the shirt collars: “Recognizing the importance of replicating major findings in psychology, we focused on recurrent claims about resilience.” They claim that previous estimates of resilience have been vastly overstated, and use a reanalysis of data we previously published to support their claim (see here and here). Their findings appear to show that less than half are resilient to spousal loss (47%); about a third to divorce (36%); and less than half to unemployment (48%).

I will argue that their conclusions are based on:

  1. questionable statistical decisions in their trajectory analyses;
  2. peculiarly strong inferences from findings that were, in fact, extraordinarily muddled;
  3. an unclear operational understanding of resilience itself.

I would also add that their study is not a replication. Instead, it is a reanalysis, as my co-authors explain here.

Methods for Determining Resilience

There are a lot of ways of determining rates of resilience. One technique that has gained a lot of currency is latent growth mixture modeling. This technique groups people who experienced adversity into different reaction patterns over time and provides a rough estimate of resilience and other reactions. These estimates, like all estimates, are subject to uncertainty. They are susceptible to model decisions and to covariates; and, like all research, to sample limitations and questions of external validity. But when done carefully, they do provide a reasonably sound index of how many people show, for example, resilience vs. PTSD reactions.

Infurna and Luthar conduct a trajectory analysis using large samples of people who experienced either the loss of a spouse, a divorce, or unemployment. They analyze an overlapping sample with the one in our original paper and use the same latent trajectory technique but with very different model specifications.

As someone who has published many trajectory studies myself, I know them from a technical and a conceptual standpoint. They require an unusual degree of judgment to carry them out, and a key issue concerns how you design your statistical model. Two concerns must be balanced. You need to provide an overall structure for your model that you think reflects the underlying data. But you also need to provide enough freedom so that the data are not arbitrarily forced into your model structure.

The balance between imposing structure and providing freedom is an inherent tension in trajectory analyses. There are no absolute rules for striking this balance. And trajectory models are inherently iterative. But there are two clear criteria that guide your decision making. One criterion is that a better model tends to be one that has a better fit to the underlying data (based on measures of relative fit). Another is that a better model is one that you can make sense of (interpret or align with existing theory).

How did Infurna and Luthar conduct their trajectory analysis? They opted, to an extraordinary degree, to increase the number of parameters of in their models and to estimate variances rather than fix them. That is, they opted against imposing structure or constraints. One potential problem with this approach is that the underlying data are poorly represented, and, as a result, the model doesn’t fit very well. In fact, they produced models that had demonstrably poor fit. For example, in their analysis of bereavement, entropy was .58, which would generally be considered poor. By contrast, in our bereavement analyses, entropy was .70.

Strangely, in the introduction, the authors advance strenuous a priori justifications for their model decisions, but at the same time, they also emphasize that latent trajectory analyses are inherently exploratory. If they are exploratory, why would you determine your model a priori? Wouldn’t you want to pay attention to the data before you settled on analytic decisions?

They also chose not to link the trajectories to relevant correlates or meaningful outcomes (as we did in our original paper). This would have helped to shed light on the meaning or validity of their trajectories. Instead, their analyses were based entirely on a single outcome measure, with no other data points brought to bear. As a result, the trajectories were, for all intents and purposes, meaningless (i.e., uninterpretable).

Don’t take my word for it. Let’s look at the preferred model they produced for bereavement. Below you’ll see two different trajectories of life satisfaction across the 11 year span of the study (the middle time point is the loss). According to the authors, one of these trajectories is resilience and one is recovery. (Data and syntax from the authors are here on Open Science Framework.)

infurna_traj

A simple question: which trajectory is resilience? If you don’t know the answer, you are not alone. I sure wouldn’t. The trajectories are identical.  Each shows a modest dip in life satisfaction around the time of the loss. Each returns to its baseline levels at about the same time. But one trajectory (the upper one) is labeled as resilience and the other (the lower one) is labelled as recovery. In fact, both trajectories could be called resilience (bouncing back to where one started), resulting in the Alice-in-Wonderland conclusion that everyone is resilient (100%).

Comparing Trajectory Results

Compare their result with the trajectory solution my colleagues and I identified in our original paper. Note that our trajectories are not only distinctive but also correspond to theoretically relevant patterns. We found a group that is substantially affected by the loss (blue trajectory; 21.3%), which represents a grief reaction. We found one that is modestly affected (black trajectory; 58.7%), which we called resilience. We also found a group that improves (green trajectory; 5.4%), a phenomenon previously documented and likely veridical. We also found a group that was low-functioning before and low-functioning after the loss, displaying little reaction (red trajectory: 14.6%). I leave it to the reader to decide which of the trajectory solutions makes more sense.

mancini_traj_2

How did they turn our original analysis into mush? By providing far too much freedom in their models. Their analysis stands apart from every other latent growth mixture model I have ever encountered in the degree to which they freed up parameters and allowed variances to be estimated rather than fixed. As mentioned, they make a strenuous argument on behalf of this decision. But ultimately, when the results make little sense, there is little support in the literature for deciding to forge ahead anyway. See Muthen in particular on this.

Expansive and Unwarranted Conclusions

Nevertheless, the authors draw expansive, unwarranted conclusions. “Considered collectively, these factors underscore the inadvisability of any declarations on rates of resilience.” But the title of the paper is “Resilience is Not as Common as Was Thought”? You can’t have it both ways.

They also argue that resilience is not distinct from recovery. “From a scientific perspective, our findings underscore the need to reexamine not only conclusions that resilience is the modal response to adversity but also that it is distinct from recovery.” The authors’ own analytic decisions played a strong hand in producing this result. However, this possibility is not acknowledged as a potential limitation of their approach.

Further confusing matters, if the latter conclusion is true—that resilience and recovery are not distinct—then the primary conclusion that resilience is not common is without foundation. 

Scientific Responsibility

In short, the authors make sweeping claims—and sweeping dismissals—on the basis of results that border on meaningless. They use single variable analyses of bereavement, divorce, and unemployment to reject conclusions supported by dozens of studies using different methods, different samples, and different traumatic events.. They use debatable procedures, and at the same time, they exhort others to employ their procedures, without considering their limitations or that they are at variance with other published work.

They even question the scientific responsibility of previous resilience researchers: “We argue, respectfully, that resilience researchers must hold themselves to the highest standards of scientific responsibility, ensuring great circumspection in conclusions drawn on the basis of particular data sets, measures, and analyses.”

Scientific knowledge is always in flux, and scientific responsibility must be borne by all. It remains possible that resilience is not common. But this paper does not demonstrate it.

References

 Bonanno, G. A. (2004). Loss, trauma, and human resilience: Have we underestimated the human capacity to thrive after extremely aversive events? American Psychologist, 59(1), 20-28. doi:10.1037/0003-066X.59.1.20

Galatzer-Levy, I. R., & Bonanno, G. A. (2016). It’s not so easy to make resilience go away: Commentary on Infurna and Luthar (2016). Perspectives on Psychological Science, 11(2), 195-198. doi:10.1177/1745691615621277

Galatzer-Levy, I. R., Bonanno, G. A., & Mancini, A. D. (2010). From Marianthal to latent growth mixture modeling: A return to the exploration of individual differences in response to unemployment. Journal of Neuroscience, Psychology, and Economics, 3(2), 116-125. doi:10.1037/a0020077

Infurna, F. J., & Luthar, S. S. (2016). Resilience to major life stressors is not as common as thought. Perspectives on Psychological Science, 11(2), 175-194. doi:10.1177/1745691615621271

Mancini, A. D., Bonanno, G. A., & Clark, A. (2011). Stepping off the hedonic treadmill: Individual differences in response to major life events Journal of Individual Differences, 32(3), 144-152. doi:10.1027/1614-0001/a00004

 

 

 

Can Trauma Improve Psychological Health?

Traumatic events are not necessarily traumatizing. In fact, traumatic events are usually not traumatizing. Most people suffer no enduring psychological consequences from them, even after events as horrific as the 9/11 terrorist attacks or a mass shooting. After decades of confusion about our capacity to cope with acute stress, we now know—based on study after study—that people have a robust and likely inherent capacity to cope effectively with trauma.

The Complex and Sometimes Paradoxical Effects of Trauma

My purpose here is not to review the evidence for resilience to trauma (see here for that). Instead, I want to suggest an even more radical idea: That trauma can—sometimes and for some people—have beneficial effects. Yes, beneficial effects.

My colleagues, Heather Littleton and Amie Grills, and I had an extremely rare opportunity to test this possibility in a study of 368 female survivors of the Virginia Tech campus tragedy in 2007, the second most deadly civilian shooting in US history. It was rare because students’ functioning (depression and anxiety symptoms) had been assessed before the shootings (as the result of an unrelated study) and again at 2, 6, and 12 months after. This allowed us to precisely gauge the impact of the shootings on their psychological health.

We expected to find a range of psychological responses to the tragedy, and we did. Most (about 60 percent) were resilient, with no statistically discernible uptick in distress after the shootings. On the other hand, about 20 percent of survivors saw large increases in anxiety or depression that continued to increase for 12 months—a reaction consistent with potential posttraumatic stress disorder. Given the typical prevalence of resilience and the indisputable potential of such events to generate distress, these findings were unremarkable.

What was remarkable was a group of survivors whose psychological health improved. This group had high levels of depression and anxiety before the shooting and substantially less anxiety and depression after the shootings. About 15 percent of the sample, in fact, saw substantial and statistically significant improvement in psychological functioning.

Social Relationships Can Be Strengthened after Traumatic Events

Why would some people improve? We hypothesized that people who felt isolated, anxious, and depressed before a traumatic event would benefit from a well-documented phenomenon: The power of acute stress to strengthen our relationships, particularly with close others. The UCLA psychologist Shelley Taylor has described this as “tend-and-befriend.” Indeed, for more than half a century, historians and sociologists have documented this phenomenon, variously describing the aftermath of mass trauma as a “post-disaster utopia,” a “city of comrades,” and “a democracy of distress.”

This is exactly what we found. Psychologically improved survivors reported a substantial increase in the belief that friends and family would be available if needed. They were more likely to report gains in intimacy with friends or family, and to perceive an increased sense, for example, that “I can count on my friends when things go wrong” and “I can talk about my problems with my family.” Remarkably, their social ties continued to strengthen for a full year after the shootings. As expected, the group with potential posttraumatic stress disorder reported no increase—and even a slight decline—in their perceptions of support from others.

“The Remedial Influences of Pure, Natural Human Relationships”

The trauma appeared to improve their relationships. And this in turn may well have improved their psychological functioning. Indeed, close and active social relationships are essential to well-being and happiness. Not surprisingly, then, psychological distress is exquisitely responsive to the quality of our relationships: The perceived absence of supportive relationships is one of the strongest predictors of posttraumatic stress disorder, a devastating and potentially chronic illness. All of this points to a fundamental and often overlooked reservoir of healing: what the novelist George Eliot once described as “the remedial influences of pure, natural human relations.”

References

Bonanno, G. A. (2004). Loss, trauma, and human resilience: Have we underestimated the human capacity to thrive after extremely aversive events? American Psychologist, 59, 20-28. doi:10.1037/0003-066X.59.1.20

Bonanno, G. A., Galea, S., Bucciarelli, A., & Vlahov, D. (2006). Psychological resilience after disaster: New York City in the aftermath of the September 11th terrorist attack. Psychological Science, 17, 181-186.

Mancini, A. D., Littleton, H. L., & Grills, A. E. (2016). Can people benefit from acute stress? Social support, psychological improvement, and resilience after the Virginia Tech Campus Shootings. Clinical Psychological Science, 4, 401-417. doi:10.1177/2167702615601001

Solnit, R. (2010). A paradise built in hell: The extraordinary communities that arise in disaster: Penguin.

Wolfenstein, M. (1957). Disaster: A Psychological Study: Free Press.

The Trouble with Post-traumatic Growth

You’ve probably heard of post-traumatic growth.  It’s been touted in the New York Times (“the surprisingly positive flip side of PTSD”), studied in countless empirical papers, and sermonized in TED talks, books, and academic research centers. It’s one of those zeitgeist ideas upon which entire empires are built: First, we had PTSD, but now we have post-traumatic growth.

The basic principle is this: Something horrendous happens (a mugging, a serious car crash, a cancer diagnosis), and in the weeks and months that follow, we have trouble not thinking about the experience. We avoid reminders of it, and we have intrusive memories that pop into our heads and ratchet up our anxiety. We are debilitated by these symptoms. But at some unspecified time later–perhaps years after–we grow from that trauma, and we become a better person. We become wiser, stronger, more accepting of others; we develop closer relationships and have more compassion for others; we change our philosophy of living, re-evaluate our priorities, and become more spiritual. All in all, we are better, because we were traumatized.

It’s an immensely appealing idea. Who wouldn’t want it to be true?

The only problem is: There’s very little evidence for it. Wait, didn’t you just say that countless empirical papers have been published on post-traumatic growth?

Yes, but here’s what almost all of those studies do. They ask people who have experienced a potentially traumatic event whether they are better off because of it. And what do you know, many people report that they are indeed a better person. They have grown. They see new possibilities in life. They are able to find in their suffering a bright kernel of redemption.

But does this mean they actually are better? In other words, are they actually wiser, more compassionate, and closer to others? Or do they just perceive that they are?

Perceived Growth and Actual Growth Are Two Different Things

It turns out that it is very difficult to separate these two things: the perception that we are better and the actuality that we are. In fact, almost no studies separate perceived and actual growth for a very good reason: It is extraordinarily difficult to know how someone is doing before a trauma occurs.

One remarkable study did just that: they measured a large sample of undergraduates (N = 1,528) at the beginning and the end of a semester. They then identified a group of participants who experienced a traumatic event during the semester that caused considerable distress  (n = 122). They asked whether they had grown from the trauma (including “I have a greater feeling of self-reliance” or “I am able to do better things with my life”). In theory, among this trauma-exposed group, if you perceived that you grew from the trauma, you should actually show improvements in your overall functioning. In other words, when you say you think you are better (perceived growth), you are in fact better (actual growth). Well, the researchers found that the perception of growth was unrelated to actual growth. Moreover, the perception of growth was linked to more distress at semester’s end.

In short, just because someone perceives they are better off does not mean that they are. In fact, it may very well mean that they are not.

Perceived Growth Is Likely a “Positive Illusion” 

Why would someone perceive that they have grown when they have not? One explanation is that perceiving growth is a way of coping with the event itself. In this framework, post-traumatic growth isn’t growth at all. It’s a “motivated positive illusion” whose purpose is to protect us from the possibility that we may have been damaged. In fact, one unusually rigorous experimental study found that when an event threatens our sense of self, we are more likely to believe that the event made us better in some way.

Alas, this coping strategy is ineffective. People who perceive growth tend to do worse over the short and the long term compared to people who don’t. How do we know? One recent study looked at soldiers returning from a deployment to Iraq. They found that soldiers who reported posttraumatic growth 5 months after returning home saw an increase in PTSD symptoms at 15 months. Another study published this year on survivors of the Oslo bombings, the horrific 2011 massacre in Norway, found the exact same result–early posttraumatic growth = later PTSD.  In short, perceiving growth portends worse functioning, not better.

Are There Benefits to Adversity?

Does this mean we cannot benefit from adversity? Absolutely not. But before we can understand how, we have to understand the difference between perceptions of change and actual change. When we conflate the two, we walk ourselves down the garden path.

However, when we focus on actual change, we find that acute adversity can benefit us. But only for some people and only under some circumstances. Indeed, these benefits may only occur among people who were highly distressed before the trauma occurred. In other words, acute adversity may paradoxically help us to feel better. In my next blog post, I’ll discuss this phenomenon in relation to a recent paper of mine on survivors of the Virginia Tech campus shootings. We’ll see that acute adversity can be–strangely and sometimes–just what the doctor ordered.