A study by researchers at the University of California, Yale, and Facebook has found that moods can spread virally through social media sites such as Facebook. Using data from millions of Facebook users, the researchers examined the impact of rainy days.
They found that for every one person directly affected by rain, one to two others would also feel the impact.The study was published in online scientific journal Plos One.
"What people feel and say in one place may spread to many parts of the globe on the very same day," wrote the report's authors.
They added the data suggests that "online social networks may magnify the intensity of global emotional synchrony".