Donald Trump’s childish Twitter jabs may not be helping his case. While the likely Republican presidential nominee is known for reducing important issues to insults and cheap shots in 140 characters or less, it turns out the tweets that resonate most are not the ones that are dumbed down, but those written at a higher reading level.

That’s according to data provided exclusively to International Business Times by the social software company Spredfast. The data show engagement (likes, comments, retweets) on Trump’s tweets peak at 11th-, 12th- and 13th-grade reading levels. At the same time, Trump (@realDonaldTrump) isn’t shy about tweeting, and the median reading level of his tweets is at the 6.4-grade level. That level is lower than that of his Democratic opponents: Vermont Sen. Bernie Sanders (@BernieSanders) has a median 7.66-grade level, and Hillary Clinton (@HillaryClinton) has a 7.06-grade level.

Spredfast pulled from the last 3,000 tweets for each candidate. For Clinton and Trump, the tweets range from late October through April 26. For Sanders, the tweets were pulled from Dec. 29-April 26. The average grade levels stay fairly consistent when compared over the last four months. Interestingly, Sanders’ average reading level drops the most, by about a half percentage point.

The distribution also aligns with the average and medians for each candidate. However, Trump’s distribution level peaks at a 4th-grade reading level whereas the majority of his tweets are below a 5th-grade reading level.

Trump hit a low grade level, 3.6, with a tweet on Fox News anchor Megyn Kelly. The tweet garnered 5,429 retweets and 17,769 likes:

A peak grade level for Trump was 13.2 on his negative portrayal in the media, with 7,294 retweets and 23,232 likes:

A 13.2-grade level tweet from Sanders focused on economic issues, with 1,532 retweets and 4,057 likes:

And for Clinton, a 13.2-grade level tweet focused on her donors, with 2,009 retweets and 7,466 likes:

While Trump may have the most engagement per tweet, his spew of unfavorable messages could lead to a demise when it comes to the general election, as New York Times columnist Farhad Manjoo argued Wednesday. Trump “has used Twitter as a tool to foment culturewide rage — it’s his big, inescapable bullhorn. Yet winning a presidential campaign involves more than simply whipping up unfocused outrage,” Manjoo wrote.  

If the Trump campaign analyzed the engagement of his tweets, as Spredfast has done, and took action to improve the metrics, the camp may find value in improving the sophistication of the messages. Trump dictates the majority of his tweets to staffers during the day and tweets from his accounts at night, according to DC Examiner reporter Gabby Morrongiello.

trump twitter A protester holds a sign outside while Republican U.S. presidential candidate Donald Trump meets with Speaker of the House Paul Ryan at the National Republican Congressional Committee in Washington, D.C., May 12, 2016. Photo: BRENDAN SMIALOWSKI/AFP/Getty Images

Yet, the engagement for Trump extends much further than the microblogging site. A single tweet about eating a taco bowl for lunch accompanied by the line “I love Hispanics” inspired dozens of media outlets to write articles or create videos about that single tweet.

Regardless of their future strategy, the three remaining candidates are not alone in low reading levels on Twitter, as illustrated by other celebrity Twitter users. (Insert sad-face emoji here.)