The research behind Closer
Closer makes some quiet claims: that two tiny check-ins can change how a year feels, that appreciating people strengthens your bond with them, and that a journal this personal should never live on someone else’s server. We didn’t invent those ideas. This page collects the research they stand on, for parents, for the curious, and for anyone who wants to check our work.
Our bar for what appears here: primary sources from named institutions, linked and dated, summarized honestly, including the findings that complicate the story. If we couldn’t verify it against the source itself, it isn’t on this page.
Screens and wellbeing
The case for spending a little less of your day inside the feed, made by the people who study it.
Nearly half of teens now say social media harms people their age
In a 2025 Pew Research Center survey of 1,391 U.S. teens, 48% said social media has a mostly negative effect on people their own age, up from 32% just two years earlier. The honest wrinkle: only 14% say it harms them personally. The harm is easiest to see in everyone else.
National survey Pew Research Center · 2025
Instagram’s own researchers found it makes things worse for girls who are already struggling
Internal Meta research, surfaced by the Wall Street Journal in 2021 and confirmed in Meta’s own public response, found that among teen girls experiencing body image issues, 1 in 3 said Instagram made them feel worse. The company’s researchers knew it years before the public read it.
Internal research, disclosed Meta’s response to the Wall Street Journal · 2021
Teens spending 3+ hours a day on social media face double the risk of depression and anxiety symptoms
The U.S. Surgeon General’s 2023 advisory reports that up to 95% of teens use social media and more than a third use it almost constantly. It highlights a study of 6,595 U.S. adolescents in which those spending more than three hours a day on social media faced twice the risk of poor mental health outcomes, including symptoms of depression and anxiety. The average for 8th and 10th graders that year: 3.5 hours.
Government advisory U.S. Surgeon General · 2023
The APA’s advice to parents: monitor early, and never let the feed crowd out sleep
The American Psychological Association’s 2023 health advisory recommends adult monitoring of social media through early adolescence (roughly ages 10 to 14), social media literacy training before use, and a hard line that social media should never interfere with sleep or physical activity, the two things most reliably tied to teen wellbeing.
Professional-body advisory American Psychological Association · 2023
The average American checks their phone 186 times a day
Reviews.org’s 2026 survey of roughly 1,000 U.S. adults found an average of 186 phone checks a day, about once every five waking minutes, and 3 hours 14 minutes of daily phone time, with Gen Z highest at just over four hours. It’s a consumer survey rather than an academic study, but its figures track the academic picture.
Consumer survey Reviews.org · 2026
The science of reflection
Closer’s ritual is small on purpose. The research on writing things down suggests small is enough.
Writing about what you actually feel is one of psychology’s most replicated low-cost interventions
The expressive writing paradigm, pioneered by James Pennebaker in the 1980s, asks people to write about an emotional experience for 15 to 20 minutes on a few occasions. Across the studies this review covers, writers had better physical and psychological outcomes than people writing about neutral topics: fewer doctor visits, improved immune markers, better mood. The honest footnote: it can sting a little in the moment before it helps.
Peer-reviewed review Baikie and Wilhelm · Advances in Psychiatric Treatment · 2005
Listing a few things you’re grateful for measurably shifts mood and outlook, modestly but reliably
Across three randomized experiments with students and adults with chronic illness, people who regularly listed up to five things they were grateful for rated their lives more favorably and felt more optimistic than comparison groups writing about hassles. In the daily version, they also slept more and woke more refreshed. The effects were real and moderate, and did not show up on every measure, which is roughly what an honest reader should expect.
Peer-reviewed study Emmons and McCullough · Journal of Personality and Social Psychology · 2003
Naming a feeling in words turns down the brain’s alarm
In a UCLA brain-imaging study of 30 adults, putting a word to the emotion on a face produced significantly less amygdala activity than a matched control task, with prefrontal regions doing the quieting. It is a mechanism study, not a treatment trial, but it is why Closer starts every check-in by asking how you feel.
Peer-reviewed study Lieberman et al. · Psychological Science · 2007
Writing three good things each night, for one week, left people happier six months later
In a randomized, placebo-controlled study of 577 adults, the group that wrote down three things that went well each day, and why, for a single week showed no immediate advantage, then measured happier and less depressed at one, three, and six months. The gains were strongest for people who quietly kept the habit going. The authors note the sample self-selected from a happiness website; it remains the best-tested small-wins exercise there is.
Peer-reviewed RCT Seligman, Steen, Park and Peterson · American Psychologist · 2005
Checking in on your mood builds the self-awareness that tracks with feeling better
In a randomized trial with 114 young people ages 14 to 24, those who monitored their mood several times a day for a few weeks grew significantly more emotionally self-aware than a comparison group, and that growth predicted falling depressive symptoms. The honest detail: both groups improved, and the benefit ran through self-awareness rather than the app itself.
Peer-reviewed RCT Kauer et al. · Journal of Medical Internet Research · 2012
Relationships
The strongest finding in all of happiness research: the people are the point.
The longest-running study of adult life keeps landing on one answer: relationships
The Harvard Study of Adult Development has followed its participants since 1938. Its central finding, in current director Robert Waldinger’s words, is that close relationships, more than money, fame, social class, IQ, or genes, are what keep people happy and healthy across a lifetime. Relationship satisfaction at age 50 predicted physical health at 80 better than cholesterol levels did.
Longitudinal study Harvard Study of Adult Development · since 1938
People with stronger social relationships had a 50% greater likelihood of survival
A meta-analysis of 148 studies covering 308,849 people found that stronger social relationships were associated with a 50% increased likelihood of survival over an average 7.5-year follow-up. The authors put the effect in the same league as quitting smoking, and above the effects of obesity and physical inactivity.
Peer-reviewed meta-analysis Holt-Lunstad, Smith and Layton · PLoS Medicine · 2010
Lacking connection can raise the risk of early death as much as smoking up to 15 cigarettes a day
The U.S. Surgeon General’s 2023 advisory on loneliness concluded that social disconnection raises the risk of premature death comparably to smoking up to 15 cigarettes a day. Loneliness and isolation increase that risk by 26% and 29% respectively, and poor connection is associated with a 29% higher risk of heart disease and a 32% higher risk of stroke.
Government advisory U.S. Surgeon General · 2023
Gratitude for a partner’s small gestures strengthened the relationship the next day, for both people
In a two-week nightly diary study of 67 cohabiting couples, gratitude from everyday interactions predicted increases in relationship connection and satisfaction the following day, for the grateful person and for their partner. Feeling indebted showed no such benefit; the authors describe gratitude as a booster shot for the relationship. It is the closest thing to a citation for Closer’s evening question: who made today better?
Peer-reviewed study Algoe, Gable and Maisel · Personal Relationships · 2010
Privacy and safety
Why we built Closer with no accounts and no servers instead of a privacy promise.
When Mozilla audited mental health apps, 28 of 32 earned its privacy warning label
Mozilla’s Privacy Not Included team reviewed 32 mental health and prayer apps in 2022 and flagged 28 of them. Twenty-five failed Mozilla’s minimum security standards, with some sharing personal information with third parties and at least eight accepting passwords as weak as a single character. Only two of the 32 met the bar.
Product audit Mozilla Foundation · 2022
The FTC ordered an online therapy service to pay $7.8 million for sharing customers’ health data with advertisers
In 2023 the FTC charged BetterHelp with sharing customers’ email addresses, IP addresses, and health questionnaire answers with Facebook, Snapchat, Criteo, and Pinterest for ad targeting, after promising to keep that data private. The order banned the practice and funded refunds. A privacy promise is only as strong as the architecture behind it.
Enforcement action Federal Trade Commission · 2023
73% of Americans feel they have little or no control over what companies do with their data
In Pew Research Center’s 2023 survey of 5,101 U.S. adults, 73% said they have little to no control over what companies do with the data collected about them, and 67% said they understand little to nothing about what companies do with it, up from 59% in 2019. Closer’s answer is not a better policy. It is that there is nothing to control: no account, no server, no data held by us.
National survey Pew Research Center · 2023
When a therapy provider’s servers were breached, 33,000 patients’ session notes were stolen
Finland’s Vastaamo psychotherapy service was breached in 2018. When it became public in 2020, the attacker moved to extorting patients directly; more than 24,000 people reported demands, and confidential therapy notes were published online when victims did not pay. The lesson Closer is built on: notes that never reach a server can never leak from one.
Documented breach Recorded Future News · 2020
Last reviewed July 26, 2026. Research moves; if something here is outdated or misread, tell us at support@closer.day and we’ll fix it.