Source: HarperCollins

In the field of psychology, we’ve seen a number of bizarre manifestations of aggressive hysteria, such as the Satanic panic of the 1980s and the sudden spread of alleged multiple personality disorder. With the rise of social media, certain images and stories “go viral.” Anyone with a product to sell wants the secret for turning an idea into a phenomenon. But while some social contagions are beneficial, others can be damaging. Is there a way to trigger the good but block the bad?

Lee Daniel Kravetz is a science journalist with a master’s degree in psychology. He found himself in Palo Alto, California, during a suicide epidemic among students who attended Gunn High School. Seemingly happy, accomplished kids with supportive families were throwing themselves in front of a train. As a new father, Kravetz wondered if there was something about this high-pressure community, which gave rise to such tech innovators as Apple, Google, and Netflix, that had infected these kids. He used the contagion to explore how infectious behavior spreads.

Kravetz looks for specific qualities before he takes on a story: “A struggle to understand and classify human behavior; unique characters confronting high stakes, moral dilemmas, and a question of personal culpability; heroes facing opponents; and oftentimes a situation in which life hangs in the balance.” His hope for Strange Contagion was to figure out how social contagions spread so we can guard ourselves against negative impulses while participating in the spread of positive ones.

Each chapter introduces readers to research on some angle that promises to shed light. Kravetz starts with how influence travels through observation. We can see for ourselves how certain YouTube videos or Facebook stories go viral, and how some types of crimes spawn copycats. He adds the idea of emotional and behavioral mirroring so that we “can create with others a harmony of movements.”

This seemingly positive trait for community cohesion also makes us vulnerable to the rapid propagation of damaging ideas. But timing is important, too, as is a favorable environment. A Satanic panic won’t just happen out of nowhere. The conditions must be right. Once a social contagion gets going, it runs in the background “like a computer’s operating system.” We remain unaware of how we’re affected. This is disturbing!

To understand mass hysteria, Kravetz says, we must examine how otherwise reasonable people can become overwhelmed with fear or caught up with someone else’s passion. “Hysteria legitimises the improbable and supersedes the logical.” It can become a continuous loop.

Kravetz talks to several different types of experts to try to understand the nature of emotional contagion. He visits a researcher, for example, who develops motivation models and discusses embodied primes. One theory features “holders of high prestige,” while another settles on the negative impact of pressure to succeed. Training in emotional intelligence might offer a solution, as might better community support. Each approach seems promising but none provides a complete answer. So, he keeps searching.

After each visit, Kravetz returns to the problem of Palo Alto’s suicides, which frame the narrative. Suicide contagion is the negative impact of an initiating suicide on vulnerable people, triggering others. If publicized in detail, the initiating incident presents a method and seems to give permission to those who have contemplated suicide to go ahead. These contagions can occur as a widespread cultural response, a local suicide cluster, or an echo cluster. Palo Alto saw five suicides from Gunn High during 2009-10, with an echo cluster in 2014.

While the topic of social contagion is itself important, among the best features of Kravetz’ exploration is his tone. It has the feel of journaling as he displays his process. “Riding the train home later that afternoon, I organize the frayed threads of new information into my evolving model…” The thing he wants to pin down seems to shift and change. “Every new component that adds power to the storm makes it that much harder to classify.” Yet this is a puzzle whose solution matters, both socially and personally. Kravetz has a significant emotional investment. He wants to resist baseless hysteria but also wants to avoid exposing his own child to some elusive, invisible force that seems to float over the area like an ethereal banshee.

Kravetz concludes that while we can understand certain components of these contagions and even put some blocks into place, it's difficult to stop one, once begun. So, we must continue to try to dissect and understand. He acquired many powerful insights from which readers will benefit but also many questions and contradictions. Media, for example, is a primary tool for perpetuation, but it can also spread countermeasures. Behavioral primes can provide standards for motivation while also fostering feelings of failure.

Strange Contagion is a thoughtful, provocative discourse about a gripping topic, providing a strong foundation for dialogue and further exploration.


Kravetz, L. D. Strange contagion: Inside the surprising science of infectious behaviors and viral emotions and what they tell us about ourselves. New York, NY: HarperCollins.

You are reading

Shadow Boxing

Day Pass for a Psychopath?

Are treatments sufficiently effective to engender trust?

MeToo: A Watershed Moment

Collection of sexual assault narratives illuminates shared trauma and healing.

Strange Motives for Serial Murder

In recent years, some serial killers have acted outside the box.