Jean Twenge
Researchers · San Diego State University
The SDSU psychologist who documented the sudden collapse in teen mental health beginning around 2012.
Jean Twenge is a psychologist at San Diego State University who has spent years tracking generational data on teen well-being, documenting a sharp decline in adolescent mental health that began around 2012 — the same period smartphones and social media became a constant presence in young people's lives. Her books "iGen" (2017) and "Generations" (2023) lay out these trends, and her 2025 book "10 Rules for Raising Kids in a High-Tech World" turns the research into practical guidance for parents. She writes the Generation Tech Substack and testified before the Senate Commerce Committee in January 2026 on the association between heavy tech use and adolescent mental health.
Suicide and self-harm are complex and never caused by one factor alone. Problematic screen use, cyberbullying, harmful content, and online exploitation may increase risk or intensify existing distress. If someone is in immediate danger or emotional crisis in the United States, call or text 988.
WORKS IN THE LIBRARY (12)
BOOKS
iGen: Why Today's Super-Connected Kids Are Growing Up Less Rebellious, More Tolerant, Less Happy—and Completely Unprepared for Adulthood
iGen is San Diego State University psychologist Jean Twenge's 2017 book arguing that Americans born from the mid-1990s onward are the first generation to spend their entire adolescence with smartphones, and that this coincides with a sharp, documented shift in teen behavior beginning around 2012. Drawing on large national surveys, Twenge describes iGen teens as spending markedly less in-person time with friends, sleeping less, and reporting higher rates of anxiety, depression, and loneliness than Millennials did at the same age — trends she links to the rise of smartphones and social media rather than treating as proof of a single cause. The book also covers non-tech generational shifts, including delayed dating, driving, and paid work. TechKids Foundation cites iGen as the originating, most widely read statement of the smartphone-era generational mental-health argument this library documents, not as a clinical or diagnostic text.
Generations: The Real Differences Between Gen Z, Millennials, Gen X, Boomers, and Silents—and What They Mean for America's Future
Generations is Jean Twenge's 2023 book analyzing survey data from roughly 39 million people across six living generations to argue that technology, more than any single historic event, is the primary force separating one generation's outlook from the next. In its Gen Z chapters, Twenge extends the case she made in iGen, presenting updated charts linking the post-2012 rise in smartphone ownership and social-media use among American teens to parallel increases in depression and loneliness and to less in-person socializing and sleep. She frames these as associations documented across multiple independent surveys, not a single proven mechanism, and situates the Gen Z mental-health trend alongside broader generational data on work, politics, and family life. TechKids Foundation cites this book as Twenge's most data-extensive update to the smartphone-generation argument, and as the source for figures she later cited in her 2026 Senate testimony.
10 Rules for Raising Kids in a High-Tech World: How Parents Can Stop Smartphones, Social Media, and Gaming from Taking Over Their Children's Lives
10 Rules for Raising Kids in a High-Tech World is Jean Twenge's 2025 parenting book, translating her research on smartphones, social media, and gaming into a step-by-step guide for households. Twenge argues that legal protections limiting children's access to inappropriate online content are weak, so she recommends parents set and enforce firm limits themselves: delaying smartphone ownership until a child is old enough to drive, backing up screen-time rules with parental-control software, and protecting time for sleep, exercise, and in-person socializing. She points to research she says shows delaying smartphone access is associated with better mental-health outcomes, and includes real-world examples — such as a family sending unsupervised, phone-free teens on a campout — to illustrate tech-free independence. TechKids Foundation cites this book as Twenge's most current, practice-oriented distillation of her research for parents and educators, published shortly before her January 2026 Senate testimony.
STUDIES
Have Smartphones Destroyed a Generation?
In this widely discussed September 2017 Atlantic cover essay, adapted from iGen, Jean Twenge lays out the generational survey data behind her argument that smartphones are associated with a marked change in American teen life beginning around 2012. She reports that teens who spend more hours a day on phones and social media are more likely to describe themselves as unhappy, to report a risk factor for suicide such as making a plan, and to sleep less than lighter users, while those spending more time with friends in person or playing sports report fewer such risk factors. The essay also documents declining in-person socializing, dating, and paid work among teens over the same period, and notes today's teens are physically safer than prior generations even as she argues they face a worsening mental-health picture. TechKids Foundation cites this as the most influential public statement of the smartphone-generation argument.
Associations Between Screen Time and Lower Psychological Well-Being Among Children and Adolescents: Evidence From a Population-Based Study
Published in Preventive Medicine Reports, this study by Jean Twenge and W. Keith Campbell analyzed a nationally representative U.S. sample of more than 40,000 children and adolescents ages 2–17, surveyed in 2016, comparing daily screen time against a range of well-being measures. Beyond roughly one hour of daily screen time, more screen time was associated with lower reported well-being — including less curiosity, lower self-control, more distractibility, and less emotional stability — with the association larger among teenagers than younger children. Among 14- to 17-year-olds, those using screens seven or more hours a day were more than twice as likely as light users to have ever been diagnosed with depression or anxiety. The authors describe these as associations from a single survey wave, not proof screen time alone causes the differences observed. TechKids Foundation cites this as one of the largest single-survey datasets supporting the broader screen-time/well-being association.
Decreases in Psychological Well-Being Among American Adolescents After 2012 and Links to Screen Time During the Rise of Smartphone Technology
Published in the APA journal Emotion, this study by Jean Twenge, Gabrielle Martin, and W. Keith Campbell drew on yearly national surveys of U.S. 8th, 10th, and 12th graders from 1991 to 2016 — about 1.1 million adolescents in total — tracking self-esteem, life satisfaction, and happiness over time. The authors report that well-being had followed gradual trends for decades but dropped suddenly after 2012, in the same years adolescents spent more time on screens and less on activities like in-person socializing, exercise, and religious attendance. Adolescents reporting a small amount of electronic communication were the happiest group overall. The authors note economic indicators like unemployment did not track with the shift, arguing against the Great Recession as the driver, and instead point to smartphone adoption as a plausible associated factor. TechKids Foundation cites this as a key study behind the 'something changed around 2012' argument.
Gender Differences in Associations Between Digital Media Use and Psychological Well-Being: Evidence From Three Large Datasets
Published in the Journal of Adolescence, this study by Jean Twenge and Gabrielle Martin drew on three large, nationally representative surveys of 13- to 18-year-olds in the U.S. and U.K. (a combined 221,096 adolescents) to examine whether digital media use is associated with well-being differently for girls and boys. Girls reported more time on smartphones, social media, and texting; boys reported more time gaming. Across all three datasets, moderate-to-heavy digital media use was associated with lower psychological well-being and more mental-health difficulties, generally larger for girls than boys. Light users reported slightly higher well-being than non-users, a benefit more pronounced among boys. In both genders, heavy users were about twice as likely as light users to score low on well-being or report mental-health difficulties, including risk factors for suicide. TechKids Foundation cites this as evidence the screen-use/mental-health association is generally stronger for girls.
Specification Curve Analysis Shows That Social Media Use Is Linked to Poor Mental Health, Especially Among Girls
Published in Acta Psychologica, this paper by Jean Twenge, Jonathan Haidt, Jimmy Lozano, and Kevin Cummins re-examines an influential 2019 paper that applied 'specification curve analysis' to three large adolescent-survey datasets and concluded the link between technology use and mental health, while real, was too small to matter practically. The authors reran the same analysis on the same datasets with different modeling choices — treating social media separately from all 'screen time,' analyzing girls and boys separately, and weighting survey subscales more evenly. Using the original approach, they reproduced the original small-association result. Using the revised approach, they found a substantially larger association between social-media use and poor mental health among girls specifically — larger, they report, than the datasets' own associations with binge drinking, sexual assault, obesity, or hard-drug use. TechKids Foundation cites this as a rebuttal to 'effect sizes are tiny' framings, at least for girls.
International Declines in Academic Performance and Increases in Loneliness Are Linked to Electronic Devices
Published in the Journal of Adolescence, this sole-authored Jean Twenge study uses the OECD's Program for International Student Assessment (PISA), which surveys 15- and 16-year-olds in dozens of countries every three years, to look for international patterns behind rising adolescent loneliness and falling standardized-test scores. Drawing on PISA rounds from 2000–2022 (over 1.7 million students across 36 countries), Twenge reports that in most countries, students' reported school loneliness rose while math, reading, and science scores fell, both shifts most pronounced between 2012 and 2022. Countries where adolescent smartphone access grew fastest, and where students reported more leisure device use during school hours, showed larger increases in loneliness and larger score declines. Twenge treats the cross-country pattern as evidence the trend is not explained by any single country's circumstances. TechKids Foundation cites this as her broadest-scope peer-reviewed study, extending her U.S.-focused argument to a global dataset.
Smartphones Are Making Today's Teens Unhappy, Psychologist Says
Days after Jean Twenge's Atlantic essay was published, NPR's All Things Considered ran this interview segment with Twenge, hosted by Audie Cornish, unpacking her generational research for a broad radio audience. NPR's own framing states that Twenge 'has observed dramatic shifts in behavior among children who go through adolescence with smartphones,' noting they are 'spending less time with friends and reporting greater anxiety' than prior generations at the same age. The segment translates the survey-based argument from her Atlantic piece and book iGen into a shorter, conversational format aimed at a general public-radio audience rather than presenting new data of its own. TechKids Foundation includes this as a documented example of Twenge's research reaching a mainstream audience through interview coverage, distinct from her own bylined writing and her academic publications.