There's an unconfirmed (but pretty solid) theory on how to tell apart genuine tweets from Donald Trump and tweets from those written by his staff. We know that Trump uses a Samsung Galaxy smartphone, and looking at data from TweetDeck we can see that tweets from @realDonaldTrump sent via Android read and sound very different to those sent from an iPhone.

Now, a data scientist has added more compelling evidence to this theory, analyzing the language and behavior used in the two types of Trump tweets to conclude that "the Android and iPhone tweets are clearly from different people." Most interestingly, compared to his ghost-written self, the real Trump uses words associated with fear, anger, and sadness.

there are different patterns of behavior for Trump's iphone and android tweets

David Robinson of Stack Overflow lays out the evidence in a blog post, analyzing roughly 1,400 tweets. He shows that Trump's (real) Android tweets are mainly sent in the morning, while those coming from an iPhone are sent in the afternoon and early evening. Also, Trump's habit of manually retweeting others (copying and pasting their tweet and surrounding it with quote marks) happens nearly exclusively in tweets sent from Android, while tweets sent via iPhone were 38 times more likely to contain either a picture or a link. Robinson points out that this makes sense, as these tweets tend to be announcements of one sort or another — exactly the sort of administrative message that campaign staff would need to publicize. Compare this, from an iPhone:

Join me in Houston, Texas tomorrow night at 7pm! Tickets: https://t.co/nvHRnfzEbH pic.twitter.com/Yd3f8xLpPl — Donald J. Trump (@realDonaldTrump) June 16, 2016

To this, from Android:

The media is going crazy. They totally distort so many things on purpose. Crimea, nuclear, "the baby" and so much more. Very dishonest! — Donald J. Trump (@realDonaldTrump) August 7, 2016

Robinson also uses sentiment analysis to compare the types of words used by Trump's Android-tweets and iPhone-tweets. The result? "Trump’s Android account uses about 40 to 80 percent more words related to disgust, sadness, fear, anger, and other 'negative' sentiments than the iPhone account does," writes Robinson, adding that "the positive emotions weren’t different to a statistically significant extent."

You can see that difference in Robinson's charts below:

So, what do we learn from this? First, it seems pretty clear that Trump's Android tweets are written by the man himself, while those from an iPhone are more likely to be the work of some poor staffer doing damage control. (Although the iPhone tweets do sometimes replicate Trump's way of speaking.) And second, that creating an atmosphere of fear, anger, distrust, and suspicion isn't just an electoral strategy for Trump — it's also part of his character.