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Study: Engaging With Social Media Can Drain Your Brain

Each decision to retweet or not saps cognitive energy, and it adds up quickly.

Source: ArtFamily/Shutterstock

The retweet is a major social currency of our time. Even if we generally aren’t reading the stuff we’re retweeting, it seems harmless enough to share whatever grabs a sliver of our interest.

But then again, maybe it’s not so harmless. So argues a new study by a research team from Cornell University and Beijing University. The researchers wondered if retweeting and otherwise sharing information online steals away mental resources that could aid in comprehending, recalling, and maybe even beneficially using the content.

Think of it as a reposting tax on your brain.

To test the theory, the researchers presented two groups of students with messages from Weibo, the Chinese equivalent of Twitter. After reading each message, one group had the option of either reposting it or going on to the next message. The other group wasn’t able to repost and could only move on to the next message. Both groups were then given a test on how well they comprehended and recalled the content of the messages.

People in the repost group had twice as many wrong answers as the non-repost group and significantly worse comprehension of the content. The comprehension results were especially bad for the messages they reposted even if they could remember the topics.

In a follow-up experiment, two groups were again presented with Weibo messages and the same repost or no-repost conditions. Then both groups read an unrelated article from a science magazine and took a test on its content. The group that reposted messages performed significantly worse on the comprehension test than the read-only group.

So what’s happening that would lead the reposters to perform worse than non-reposters in both experiments? The researchers think it comes down to “cognitive overload”—it’s not the content but the decision to share it or not that drains mental resources.

"The sharing leads to cognitive overload, and that interferes with the subsequent task," said Qi Wang, professor of human development in the College of Human Ecology at Cornell University.

The additional mental drain might be small in each “to share or not to share” case, but cumulatively it’s not so small. Consider how many times in any given day (or in any given hour of any day) we make these choices. That little tax adds up, and the new research suggests that it takes a toll on anything else we need our cognitive faculties to accomplish.

"In real life when students are surfing online and exchanging information and right after that they go to take a test, they may perform worse,” added Wang.

I'm not sure if this result amounts to an endorsement for mindlessly sharing stuff (which presumably requires less thought), but it's interesting to consider how even tiny brain drains add up and draw away juice from other things. Something to think about —after you retweet this post.

The study was published in the journal Computers in Human Behavior.

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