Human communication

Hotter days bring out hotter tempers, study finds

As temperatures rise around the world, scientists have documented large-scale environmental effects – rising sea levels, drought and famine, intense flooding and loss of species.

But increasingly, some researchers worry that higher temperatures could also contribute to people’s poor behavior.

Two recent studies add to the idea by showing that when it’s hot, people are more prone to hate speech and hostile behavior.

A study has found that hate speech on social media escalates with high temperatures. Another reported an increase in workplace harassment and discrimination at the US Postal Service when the temperature exceeded 90 degrees.

Together, the studies add to a growing literature that links heat to aggressive behavior.

Online hate speech is heating up to high temperatures

It is well known that social media brings out bad behavior. The heat further fuels the flames.

Researchers from the Potsdam Institute for Climate Impact Research have found an increase in hate speech of up to 22% on Twitter when temperatures are above 107 degrees. They also found that extreme cold boosted offensive tweets, with a 12.5% ​​increase when it was below 27 degrees.

To determine the relationship between hate speech and temperature, researchers used a machine learning algorithm to analyze 75 million hateful tweets from a database of more than 4 billion tweets posted by people at home. across the United States between 2014 and 2020. The tweets covered 773 cities across the country.

The researchers relied on the definition of hate speech from the UN Strategy and Plan of Action: any type of verbal, written or behavioral communication, which attacks or uses derogatory or discriminatory language in reference to a person or to a group on the basis of who they are, in other words, based on their religion, ethnicity, nationality, race, color, ancestry, gender or any another identity factor.

Aggressive behavior was lowest between 54 and 70 degrees, according to the peer-reviewed study, published in the Lancet Planetary Health journal. While the researchers found that the “wellness window” varies across climate zones, temperatures above 81 degrees were consistently linked to a significant increase in online hate across all climate zones.

“It points to the limits of our ability to adapt to extreme temperatures,” said Leonie Wenz, study co-author and researcher at the Potsdam Institute for Climate Impact Research.

As summers heat up and the number of heat waves increases, researchers fear an increase in online hate. The summer of 2022 ranked among the world’s hottest summers on record, according to NASA and the National Oceanic Atmospheric Administration.

“I think living in a climate-impacted world increases our stress and insecurity, we’ll also see an increase in online aggression,” said Libby Hemphill, a University of Michigan associate professor who studies hate speech and social media, who did not participate in the study.

There is hate speech and other forms of aggression whenever people feel ‘threatened’, according to Hemphill, which can lead people to make “bad decisions”.

“It makes sense to me that the climate threat would have the same or similar impact on all these other types of threats that stress people out and make them go wild,” she said.

Heat increases harassment and discrimination cases at US Postal Service

From the scorching temperatures of the Southwest to the stifling humidity of the Southeast, postal workers must ply their trade in harsh conditions, which are only getting worse as heat waves lengthen, multiply and intensify .

In recent years, postal workers have walked out due to sweltering temperatures in facilities without air conditioning and complained of unbearable working conditions.

A 2019 report from the Center for Public Integrity said the Occupational Safety and Health Administration cited the USPS for “exposing approximately 900 employees nationwide to the risk of heat-related illness and death” since 2012.

Lawmakers have held hearings on the issue and proposed legislation to address the issues.

Working in such stifling and dangerous conditions has subjected some postal workers to a hostile working environment. The peer-reviewed study published last month in the Proceedings of the National Academy of Sciences found that on days above 90 degrees, workers faced increased workplace harassment and discrimination from managers and supervisors.

The study, by PhD candidate Ayushi Narayan of Harvard University, examined more than 800,000 equal employment opportunity charges filed by USPS employees between 2004 and 2019. report found that EEO incidents increased by about 5% on days over 90 degrees compared to days with high temperatures. between 60 and 70 degrees.

Complaints came from more than 12,000 USPS offices across the country.

“I find incidents increase when temperatures are high,” Narayan said. “Reducing environmental exposure to extreme heat, whether through climate policies or various adaptations, could reduce the degree of discrimination experienced by workers.”

The USPS did not immediately respond to questions about the study, and the American Postal Workers Union declined to comment.

Lower temperatures and temperaments

Heat as an aggravator is not a new concept. For years, psychologists and social scientists have documented the relationship between high temperatures, aggressive motivation and behavior, and criminality.

Some researchers point out that the human body generates adrenaline in response to excessive heat, which can lead to aggression as a side effect. Some indicate that hot temperatures increase heart rate, testosterone, and other metabolic responses that trigger “fight or flight” responses.

Craig Anderson, professor of psychology at The University of Iowa, which has studied the relationship between violence and heat since 1979, wrote that climate change will directly increase human aggression and violence through what he calls the “heat effect”. The effect suggests that when people become uncomfortably hot, they become more irritable, think more aggressively, perceive other actions with hostility, and behave more violently.

“As global warming increases, there will be, in fact there already is, an increase in how often people have uncomfortable heat or uncomfortable heat,” Anderson said in an interview. “That in itself can lead to more aggressive decision-making and behaviors and, in some circumstances, can lead to an increase in violent behavior.”

Other field studies Anderson reviewed found that homicides, major assaults, police calls, domestic violence, and other violent behaviors all increase when temperatures are warmer.

Experts agree that slowing climate change can control heat-ignited behaviors.