📲✖️Should phones be banned in classrooms? Our study with 17,000 students finds: Removing phones improves grades, especially for struggling students! 🧵 (with @andbjn and P. Choudhury) Half of global education systems have phone bans in classrooms, particularly in K-12 settings, BUT these policies are exercised with an absence of a large-scale controlled study. Little is known about whether or how they work ( This is where our research comes into play. We partnered with 10 higher education institutions. Half of the students had to put their phones in a box during lectures throughout a semester. 💡Findings: 1. Better grades: Mandatory phone deposition boosted grades by 0.078 standard deviations, about the same effect as the gap between having a very good or a mediocre teacher for a year. First-year, lower-performing, and non-STEM students benefited the most. 2. Students liked it: Students experiencing the ban became significantly more supportive of phone ban policies. Many policymakers worry as ban policies appear restrictive. Increased support after first-hand experience is an important indicator for phone bans being a realistic, non-invasive policy. 3. No major side effects: there was a mild uptick in FOMO, but no adverse effects on student distraction, well-being, academic motivation, digital use, or online harassment. 🎯 We also did spot checks! 4. A healthier classroom environment: study coordinators randomly visited thousands of lectures to take a peek into the classroom dynamics. Students were observed as less chit-chatting and disrupting the lecture, along with reduced phone usage(!) and increased engagement by teachers.