Every day roughly 126 million people hop on Twitter to participate in a near-instantaneous flow of information, and it's making users more stupid according to a team of Italian researchers.

While analyzing the impact of Twitter when used to teach literature, economists at the Catholic University of the Sacred Heart in Milan found that it doesn't just fail as an educational aid, it actually reduced standardized test scores between 25% - 40% of a standard deviation.

"It’s quite detrimental," lead author Gian Paolo Barbetta told the Washington Post. "I can’t say whether something is changing in the mind, but I can say that something is definitely changing in the behavior and the performance."

To the best of Barbetta’s knowledge, his study is the largest and most rigorous examination of Twitter’s effect on student achievement, with applications to learning and information retention in other areas of life. The investigation drew on a sample of roughly 1,500 students attending 70 Italian high schools during the 2016-2017 academic year. Half of the students used Twitter to analyze “The Late Mattia Pascal,” the 1904 novel by Italian Nobel laureate Luigi Pirandello, which satirizes issues of self-knowledge and self-destruction. They posted quotes and their own reflections, commenting on tweets written by their classmates. Teachers weighed in to stimulate the online discussion. The other half relied on traditional classroom teaching methods. Performance was assessed based on a test measuring understanding, comprehension and memorization of the book. Using Twitter reduced performance on the test by about 25 to 40 percent of a standard deviation from the average result, as the paper explains. Jeff Hancock, the founding director of the Stanford Social Media Lab, described these as “pretty big effects.” -WaPo

The decline was most noticeable among higher-achieving students, which the paper says bolsters the conclusion that blogs and social media websites actively impair performance instead of simply failing to augment learning.

University of Southern California's Karen North, a professor at the Annenberg School for Communication and Journalism, said that the study had stark implications when it comes to politics - though the findings are hardly surprising.

"It’s the same problem that we have with the level of political discussion," said North. "People get 280 characters, and it’s not enough. Without the full background, you’re more likely to be led astray ... Remember when we were debating whether people have the attention span to consume 280 characters, instead of just 140?"

The problem according to Barbetta, the lead author, is that people will take shortcuts when they can.

"But a shortcut won’t take you to the destination in this case," he added. "It will take you somewhere different."

And Twitter is the ultimate shortcut.

Barbetta suggested that declining performance among students who had used the social networking site to study the novel was a result of two factors. The first was a mistaken belief on the part of students that they had absorbed the book by circulating tweets about its contents. The second was that time spent on social media simply replaced time spent actually poring over the book. The study contributes to growing skepticism that human activities — and learning, specifically — can be transferred to cyberspace without a cost. For instance, analysis has found that screen-based reading lends itself to skimming. In a 2016 study, it was discovered that test scores were lower among American undergraduates assigned to classrooms where computers were allowed than among those required to resort to pen and paper. In the case of Twitter and Italian literature, the initial assumption of the study turned out to be faulty. “We thought we were testing a positive intervention,” Barbetta said. -WaPo

In short, your cane-shaking grandfather was right about these new-fangled ways of communicating.