Feeling down? Happy? Angry? No matter how you're feeling, you can now blame it on your friends' most recent Facebook posts.
A new study published in the journal PLOS ONE discovered that emotions can spread via Facebook. While positive Facebook posts tend to generate other positive posts, negative posts tend to generate negative ones. But here's the good news: Positive posts tend to be more "contagious" than the negative variety.
"For every one happy message that you write, our study suggests that your friends who live in other cities will be influenced by that to write an additional one or two posts themselves," said study author James Fowler, a professor at the University of California, San Diego.
"That means that these emotions that you're feeling and expressing aren't just felt by you, they're felt by your friends as well," Fowler told Live Science.
Previous research has shown that emotions, whether positive or negative, can indeed be contagious.
In the new study, Fowler and his colleagues analyzed anonymous data on Facebook status updates from the top 100 most densely populated cities in the United States between January 2009 and March 2012. The researchers used rainy weather as an instrument, measuring how people reacted to drizzly skies in their Facebook posts and how their posts in turn affected what their friends wrote.
"If it rains on your friend in New York, is it making you a little more miserable on a sunny day in San Diego?" Fowler said, describing the question the study aimed to address.
The answer, the researchers discovered, is yes.
The findings may have both positive and negative consequences for the public, Fowler said.
"Now, more than ever, we feel what the world feels," he said.