Critics often lampoon President Trump for adding the emotion-laden "Sad!" at the end of his tweets, but his style likely carried his message far.

• A new study finds tweets that contain moral and emotional words spread further among people with similar political leanings. Trump is an obvious example of what the study shows, Verge wrote.
• Researchers studied 560,000 tweets around three hot-button topics (gun control, climate change and same-sex marriage) and discovered that re-tweets increased by 20% for each added word that expressed emotion or moral outrage. Tweets were especially contagious within like-minded ideological networks.
• "These findings offer insights into how moral ideas spread within networks during real political discussion," the New York University researchers wrote in the Proceedings of the National Academy of Sciences.