Overview

Sociogenic illness (also termed “psychogenic illness” or “mass psychogenic illness”) refers to symptoms of illness — physical or psychological — that spread through social transmission rather than from a biological pathogen, toxin, or shared environmental cause. The illness is real to those who experience it, but its origin is in social influence: seeing others with symptoms, believing oneself to be at risk, and the well-documented human capacity for emotional and behavioral contagion. Historically confined to face-to-face communities, sociogenic illness spread through television in the 20th century; since the early 2010s it has found its most powerful vector yet in social media.

Historical background

In 1997, Leslie Boss (U.S. Centers for Disease Control) published a review of sociogenic epidemics throughout history and identified two recurring variants:

Boss found consistent patterns across outbreaks: adolescent girls are at highest risk; outbreaks are more likely following unusual stressors to the community; and the illness spreads along social networks. Writing in 1997, at the dawn of the internet, she predicted that new mass communication technologies “increase the ability to enhance outbreaks through communication.”

Social media as a vector: mass social media-induced illness

In 2021, a group of German psychiatrists led by Kirsten Müller-Vahl documented a new phenomenon: young people, predominantly female, arriving at clinics with tic disorders that closely mimicked a single German influencer who had genuine Tourette’s syndrome. The researchers identified this as a new type of outbreak, “spread solely via social media,” and proposed the term “mass social media-induced illness.” The treatment doctors prescribe: get off social media.

A similar outbreak affected Anglo countries: some girls developed tic disorders involving head shakes and randomly shouting the word “beans” after exposure to a British influencer named Evie who modeled those behaviors.

Mechanism: emotional contagion + prestige bias + audience capture

Jonathan Haidt identifies two psychological processes that, working together, drive sociogenic illness on social media:

  1. Emotional contagion: People unconsciously absorb the emotional states of those they observe. Research by Nicholas Christakis and James Fowler found that depression is significantly more contagious than happiness, and that depression spreads primarily through women. When adolescent girls became hyperconnected via Instagram and TikTok after 2012, they formed a global network for emotional contagion.

  2. Prestige bias + audience capture: Humans have an evolved tendency to identify the most prestigious individuals in a community and copy them (prestige bias). On social media, the way to gain prestige is to be more extreme. Influencers who present with more extreme symptoms rise faster, becoming the models that others lock onto for social learning. This process is known as “audience capture”: the audience trains the presenter to become an ever more extreme version of whatever the audience wants to see.

The combination means that social media does not merely transmit disorders passively; it actively selects for their most dramatic and extreme expressions, concentrating them in the most visible accounts, and then amplifies them through conformity bias.

Disorders spreading sociogenically via social media

Evidence suggests multiple disorders have been spreading sociogenically, especially via TikTok, YouTube, and Instagram:

Why adolescent girls are most vulnerable

Sociogenic illness has always struck adolescent girls at higher rates than any other group. Haidt offers additional reasons specific to the social media era:

Resources