Online ‘Hate Speech’ Increases With Extreme Temperatures, Study Finds

Extreme temperatures can lead to an increase in online “hate speech,” according to a new study by researchers from the Potsdam Institute for Climate Impact Research (PIK).

The United Nations defines hate speech as “any kind of communication in speech, writing or behaviour, that attacks or uses pejorative or discriminatory language with reference to a person or a group on the basis of… their religion, ethnicity, nationality, race, colour, descent, gender or other identity factor,” which was the definition used by the researchers for the study.

In the study, the research team looked at the effect temperature has on hate speech on Twitter and interpreted the results through the lens of the relationships between human behavior, climate change and mental health.

“We found that both the absolute number and the share of hate tweets rise outside a climate comfort zone. People tend to show a more aggressive online behavior when it’s either too cold or too hot outside,” said scientist at PIK and lead author of the study Annika Stechemesser, as The Guardian reported.

The study, “Temperature impacts on hate speech online: evidence from 4 billion geolocated tweets from the USA,” was published in the journal The Lancet Planetary Health.

The researchers analyzed around four billion geolocated tweets and found misogynist, homophobic and racist tweets increased as much as 22 percent when temperatures reached more than 107.6 degrees Fahrenheit, reported The Guardian. Hate speech went up as much as 12 percent when temperatures fell to less than 26.6 degrees Fahrenheit.

Between 2014 and 2020, the scientists used machine-learning to pinpoint about 75 million tweets that contained hate speech in 773 cities in the U.S. They then compared the data to local temperature variations.

The team found that the least number of hate speech tweets happened in temperatures ranging from 59 to 64.4 degrees Fahrenheit. However, when the mercury was less than 53.6 degrees Fahrenheit or more than 69.8 degrees Fahrenheit, the number of hate tweets started to increase.

The researchers said the inflammatory tweets occurred in all climate zones, no matter the residents’ income or religious or political stance.

Anders Levermann, a researcher at PIK and one of the study’s authors, said even in areas where the residents were wealthy enough to be able to afford air conditioning or other ways to grapple with increased temperatures, hate speech went up on days that were exceptionally hot, The Independent reported.

“[T]here are likely limits of adaptation to extreme temperatures and these are lower than those set by our mere physiological limits,” said Levermann, as reported by Euronews.

Hate speech transmitted online can have negative impacts like anxiety and depression for the recipient, according to The Guardian.

“Being the target of online hate speech is a serious threat to people’s mental health. The psychological literature tells us that online hate can aggravate mental health conditions especially for young people and marginalised groups,” Stechemesser said, as Euronews reported.

In one study by the United Nations, nearly three-quarters of women from all over the world expressed being subjected to violence on the internet, and one quarter of Black people in America have reported being racially harassed online, The Guardian said.

The researchers chose Twitter because of the geolocation of many of its tweets and because a fifth of Americans use the platform. Between midday and late afternoon, when peak temperatures are usually recorded, is also high time for tweeting.

“For centuries, researchers have grappled with the question of how climate conditions affect human behaviour and societal stability,” said PIK researcher and one of the study’s authors Leonie Wenz, as reported by The Independent. “Now, with ongoing climate change, it is more important than ever.”