Scientists have shown that extreme heat changes how people feel globally. Over one billion social media posts from 157 countries were analysed. Results revealed that above 35°C, negative emotions rose sharply. The strongest declines in mood appeared in poorer regions compared to wealthier nations.
MIT researchers and partners rated each post for sentiment and connected it with local weather. They found people in low‑income countries were three times more affected by heat stress than those in high‑income areas.
Behaviour and High Temperatures
Previous studies confirm how heat worsens tempers. Drivers honk more in hot traffic, writers use harsher language, and violence tends to increase. In Greece, a large share of murders occurred on days warmer than 25°C. Historical records also show political unrest and uprisings peaking in the hottest months. Hot weather has been associated with higher suicide rates as well.
Experts suggest hot conditions may disrupt serotonin levels or raise hormones that trigger aggression. Still, they caution that these effects often combine with social and economic pressures.
Preparing for Tomorrow
Climate models predict a 2.3% global decline in positivity by 2100 as heat intensifies. Vulnerable groups such as children and the elderly, less present on social media, may suffer heavier impacts.
Researchers warn that building resilience must include both emotional and physical adaptation. Addressing heat’s psychological toll is essential in a warming world.
