Studies
The serious studies on our phones, gathered in one place and summarized in plain English. Every figure links to its source: a published paper, not a rumor.
Nearly 800 people. Those who had left their phone in another room did better on memory and reasoning tests than those who had it on the desk, even switched off.
Ward, Duke, Gneezy and Bos, Journal of the Association for Consumer Research, 2017In two experiments, students did attention tasks with a phone or a notebook placed near them. On the most demanding tasks, the presence of the phone alone was enough to lower their scores.
Thornton, Faires, Robbins and Rollins, Social Psychology, 2014Getting a notification during an attention task triples the likelihood of making a mistake, as much as replying to a message does.
Stothart, Mitchum and Yehnert, Journal of Experimental Psychology, 2015221 people spent one week with their phone alerts on and one week with them off. With alerts on, they reported more inattention and hyperactivity.
Kushlev, Proulx and Dunn, CHI 2016We now stay on the same screen for 47 seconds on average before switching to something else, compared with two and a half minutes in 2004.
Gloria Mark, University of California, Irvine, Attention Span, 2023A quarter of waking time, for personal use. 42% of French people feel they spend too much time on screens, and one in four goes over five hours a day.
Baromètre du numérique 2025 (Digital Barometer), Arcep and CrédocIn 2023, 35% of French internet users aged 15 to 74 had already tried to reduce their screen use, and half of those under 30. One in four says they cut into their sleep to stay in front of a screen.
Insee Focus no. 329, Valentin Guilloton, 2024A meta-analysis of 106 comparisons between what people report and what their device measures: the two only moderately agree, and estimates are rarely accurate.
Parry, Davidson, Sewall et al., Nature Human Behaviour, 2021Students limited to 10 minutes a day on Facebook, Instagram and Snapchat felt markedly less lonely and less depressed three weeks later.
Hunt, Marx, Lipson and Young, Journal of Social and Clinical Psychology, 20182,743 people. Those who deactivated Facebook for four weeks spent more time with friends and family, and felt slightly happier.
Allcott, Braghieri, Eichmeyer and Gentzkow, American Economic Review, 20201,095 people in Denmark. Those who quit Facebook for a week said they were more satisfied with their lives and felt more positive emotions than those who carried on.
Tromholt, Cyberpsychology, Behavior, and Social Networking, 2016Reading on a screen before bed instead of a paper book delays falling asleep, reduces melatonin and makes you less alert the next morning.
Chang, Aeschbach, Duffy and Czeisler, PNAS, 2015A review of 67 studies in children and teenagers: in 90% of them, more screen time went with shorter or later sleep.
Hale and Guan, Sleep Medicine Reviews, 2015Two strangers talk for ten minutes. With a phone lying near them, they feel less close, especially when the topic matters.
Przybylski and Weinstein, Journal of Social and Personal Relationships, 2013In the United States, time spent in person with friends fell by about 70% among 15 to 24-year-olds between 2003 and 2020, according to the Surgeon General's official advisory on loneliness.
U.S. Surgeon General, Our Epidemic of Loneliness and Isolation, 2023619 people: a week without a smartphone, one hour less a day, or no change. Cutting one hour improved well-being and lifestyle, and the effect held up better than quitting entirely, four months later.
Brailovskaia et al., Journal of Experimental Psychology: Applied, 2023280 people over six weeks. With a pause and the option to give up, they abandoned 36% of openings and tried 37% less often to open the targeted apps.
Grüning, Riedel and Lorenz-Spreen, PNAS, 2023About 220 students. After switching their phones to black and white, they used them 39 minutes less per day.
Holte and Ferraro, The Social Science Journal, 2020Three ideas keep coming back from one study to the next. First, the phone costs us attention even when we're not using it: lying on the table, or when a notification comes in. Second, that time is taken from what matters most, sleep and the people we love. Finally, and this is the good news, simple changes work: one hour less a day, a pause before opening an app, a black-and-white screen, ten minutes of social media instead of an hour.
So the problem isn't knowing what to do, but sticking to it. A study by Insee, France's national statistics office, shows that one internet user in three has already tried to limit their screen time. That's why Livetime puts these solutions in the one place you can't avoid: the home screen. We explain it in detail in why willpower isn't enough.
We only keep published work, with a link to its source, ideally its DOI, the permanent identifier of a scientific paper. We summarize what they measure, without making them say more. And we leave out figures that circulate with no origin, like the one about the goldfish having a longer attention span than us: no study has ever measured it.
Is a study missing, or does a summary seem inaccurate? Write to us from the app, with “Write to the team”, and we'll fix it.