New research found the One Direction star is the happiest celeb on Twitter.
Scientists analysed the tweets of the 100 people with the most Twitter followers, and scrutinised every word.
Other happy tweeters were Adele, and Ariana Grande.
Adoreboard, the analytic firm who conducted the research, studied the social media of each celebrity from the last eight months.
They used smart software to interpret any emotions the stars had conveyed in 140 characters.
Amazingly, the software can detect rage, joy, trust and annoyance.
Somewhat unsurprisingly, results showed singer Chris Brown as the most miserable.
Other cheerful celebs that made it into the top 20 included footballer Cristiano Ronaldo, actress and feminist icon Emma Watson, and Britney Spears.
Chris Johnston, chief executive of Adoreboard, told BT online: "Not only is Harry Styles one of the most popular celebs on Twitter with over 24 million followers but is also the most upbeat in terms of mood.
"Styles has become a global brand and like any brand is conscious how he communicates online. The study provides a new dimension by looking at the impact of specific emotions that people communicate on platforms like Twitter."
For exclusive competitions and amazing prizes visit Reveal's Facebook page NOW!