Qualité des preuves 4.88/5
Score d’évaluation en huit dimensions selon la grille de qualité . Chaque dimension notée de 1 à 5.
- D1 Ancrage des sources
- 5/5
- D2 Autorité des sources
- 5/5
- D3 Arithmétique
- 5/5
- D4 Incertitude
- 5/5
- D5 Portée
- 5/5
- D6 Prose
- 5/5
- D7 Honnêteté sur la perception
- 4/5
- D8 Complétude des réserves
- 5/5
Comment le risque varie
Le chiffre principal est une moyenne sur des situations très différentes. Voici comment la probabilité varie selon le scénario ou le contexte :
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No reliable per-user probability can be assigned. Correlational studies find small negative associations with well-being (r ≈ 0.035-0.15), but these are measured on continuous scales, not as binary harm incidence. For the typical teen user at moderate usage levels, the population-level effect size is too small and too heterogeneous to convert into a meaningful individual risk number.
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Heavy use is associated with larger negative effects in most studies, but the dose-response curve is inconsistent across datasets and may reflect reverse causation (teens who are already struggling use social media more). No study has produced a reliable incidence rate for clinical-level harm among heavy users specifically.
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The largest documented subgroup effects in the literature. Facebook/Instagram internal research (2021) and several external studies find that girls with pre-existing internalising symptoms report the most negative experiences. Effect sizes are larger than the population average but still measured on well-being scales rather than as binary harm rates. This is the subgroup where the case for a clinically meaningful effect is strongest and where a per-user probability would be most useful — but the evidence does not yet support one.
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Most studies find smaller or null associations between social media use and well-being outcomes in boys compared to girls. Some studies find positive associations with social connection. The gender difference is one of the more consistent findings in the literature, though it may partly reflect differences in platform use patterns (visual comparison-based content vs. gaming/interest-based content) rather than a biological sex difference.
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A distinct and newer exposure from feed-based social media. Common Sense Media (2025) found 72% of US teens have used an AI companion and about half use them regularly, but adoption rate is not a harm rate. The hypothesised mechanism — a private, always-available, sycophantic chat that can isolate a teen and fail to interrupt an escalating crisis — is drawn from individual cases (the Sewell Setzer III suicide and Garcia v. Character.AI; the OpenAI/Adam Raine case) and litigation now settling (the Google/Character.AI settlement in principle, January 2026), not from any cohort study with an incidence rate. No reliable per-user probability exists for crisis or self-harm outcomes tied to companion-bot use; the evidence base is adoption surveys and case reports, not population data.
La longueur et la teinte de la barre classent ces scénarios les uns par rapport aux autres, pas par rapport à d'autres risques. Les probabilités exactes sont indiquées à côté de chacun.
Décisions que ce risque éclaire
Choix qui dépendent de ce risque : comment on pèse le compromis.
Accès de l'enfant aux réseaux sociaux
% regrettent ce choix
L'action domine
Regret d'action 5.4× plus élevé
Smartphone pour enfant : quand ?
% regrettent ce choix
L'action domine
Regret d'action 13.0× plus élevé
Choisir le comparé
Cette entrée porte le drapeau no_reliable_estimate (pas d’estimation fiable), et la raison mérite d’être expliquée : la littérature de recherche sur les médias sociaux et la santé mentale des adolescents a produit des milliers d’études, de multiples avis gouvernementaux et au moins un livre à succès, mais elle n’a pas produit de probabilité défendable par utilisateur de « préjudice psychologique grave ». Les analyses corrélationnelles les plus robustes — l’étude de courbe de spécification d’Orben et Przybylski de 2019 portant sur plus de 350 000 adolescents, et les revues post-2023 synthétisées par Odgers et Jensen — trouvent des associations dans la fourchette de r = 0,035 à r = 0,15. Ces chiffres ne sont pas nuls. Ils ne sont pas non plus suffisamment importants pour être convertis en une affirmation significative telle que « 1 adolescent sur X subira un préjudice grave ». Les mesures de résultat sont des échelles continues de bien-être, et non des seuils de préjudice binaires, et l’écart entre « a obtenu un score légèrement inférieur à un questionnaire de satisfaction de vie » et « a développé un trouble d’anxiété clinique à cause d’Instagram » est un fossé que les données ne peuvent pas combler.
L’écart de perception ici va dans une direction inhabituelle. L’avis de 2023 du US Surgeon General — le document unique le plus faisant autorité sur le sujet — déclare explicitement que « nous n’avons pas encore suffisamment de preuves pour déterminer que les médias sociaux sont suffisamment sûrs pour les enfants et les adolescents ». Ce cadrage, combiné à la fuite des recherches internes de Facebook/Instagram et au livre de Haidt « The Anxious Generation », a poussé l’intuition publique à considérer les médias sociaux comme un danger clair et actuel pour la plupart des adolescents. La littérature corrélationnelle soutient une affirmation plus faible : il existe une association réelle mais faible au niveau de la population, avec des effets plus importants concentrés dans des sous-groupes spécifiques (filles âgées de 13 à 15 ans, adolescents présentant des symptômes d’intériorisation préexistants, utilisateurs intensifs de plus de 3-4 heures par jour). La question centrale ouverte est de savoir si ces effets de sous-groupes constituent une crise causale de santé mentale ou s’ils reflètent une causalité inverse et des facteurs de confusion, et la réponse honnête en 2026 est que le domaine ne l’a pas résolue.
Là où le chiffre importerait le plus — pour le parent d’une fille de 14 ans qui souffre déjà d’anxiété et passe quatre heures par jour sur Instagram — c’est précisément là que les preuves sont les plus suggestives et les moins précises. La recherche interne de Facebook a révélé que 32% des adolescentes qui se sentaient déjà mal dans leur corps ont déclaré qu’Instagram aggravait la situation, mais « se sentir pire » dans une enquête interne n’est pas la même chose que « développer une condition diagnostiquable », et l’enquête n’était pas représentative de la population. Tant que le domaine ne s’accordera pas sur une définition clinique des résultats et ne la mesurera pas prospectivement dans une grande cohorte représentative, cette entrée restera signalée comme n’ayant pas d’estimation fiable. Ce n’est pas une déclaration selon laquelle les médias sociaux sont sûrs. C’est une déclaration selon laquelle les preuves, en l’état actuel, ne soutiennent pas un chiffre spécifique.
Pour aller plus loin
Dommage des reseaux sociaux chez les ados : aucune estimation causale fiable malgre des annees d'etude. Harcelement scolaire du 6e au 12e : 65%. La panique morale sans preuve obtient des auditions au Congres. L'epidemie mesuree obtient des affiches dans le couloir.
54% des parents ayant laissé leur enfant ouvrir des comptes sur les réseaux sociaux le regrettent. Chez les parents ayant retardé ou bloqué l'accès, le taux de regret estimé est d'environ 10%.
Registre des sources
Chaque chiffre ci-dessous correspond à ce que la source a rapporté, avec la citation textuelle sur laquelle nous nous sommes appuyés et la méthode de calcul. Cliquez sur un lien pour vérifier directement.
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[1] Office of the U.S. Surgeon General (2023) — Social Media and Youth Mental Health: The U.S. Surgeon General's Advisory
Social Media and Youth Mental Health: The U.S. Surgeon General's Advisory- Statistique
The advisory states there is 'not enough evidence to determine that social media is sufficiently safe for children and adolescents' and calls for urgent action, while noting the evidence base is insufficient to establish causation or quantify per-user risk- Extrait
“"We do not yet have enough evidence to determine that social media is sufficiently safe for children and adolescents." ”
- Données source de
- 2023-05-23
- Consulté le
- 2026-04-18 · copie archivée
- Calcul
- The Surgeon General's Advisory is the highest-profile US government statement on teen social media risk. It is cited here as an authoritative framing document, not as a source of a specific probability. The advisory explicitly avoids stating a per-user risk figure and notes the evidence base is insufficient to determine whether social media is safe. It summarises the correlational literature and calls for more research, platform transparency, and legislative action. No native or normalized probability is derived from this source because the entry is flagged no_reliable_estimate.
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[2] Nature Human Behaviour (Orben & Przybylski 2019) — The association between adolescent well-being and digital technology use
The association between adolescent well-being and digital technology useSee all 2 Likelier entries citing this source →
- Statistique
Across three large-scale datasets (total N > 350,000), the association between digital technology use and adolescent well-being was negative but small: r = −0.035 for social media use specifically, explaining about 0.4% of the variance in well-being — less than the negative association with wearing glasses or eating potatoes- Extrait
“"The negative effect of technology use on adolescent well-being is small — explaining at most 0.4% of the variation in well-being." ”
- Données source de
- 2019-01-14
- Consulté le
- 2026-04-18 · copie archivée
- Calcul
- Orben & Przybylski 2019 is the most-cited methodological counterweight to the crisis narrative. The specification-curve analysis across all defensible analytic choices produces effect sizes that are statistically significant (large N) but tiny in practical terms. r = −0.035 for social media use means the association explains roughly 0.12% of the variance in well-being. This is not zero, but it is far too small to convert into a per-user probability of "serious psychological harm" — the outcome variable is a continuous well-being scale, not a binary harm threshold. This source is the primary basis for the no_reliable_estimate designation: the effect is real but not meaningfully translatable into individual risk.
- Indépendance
- Fully independent of the Surgeon General's Advisory and the Facebook internal research. Uses UK Understanding Society, YRBS, and MCS datasets.
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[3] American Psychological Association (2023) — Health Advisory on Social Media Use in Adolescence
Health Advisory on Social Media Use in AdolescenceSee all 2 Likelier entries citing this source →
- Statistique
The APA identifies social media as neither uniformly beneficial nor uniformly harmful, and notes that effects depend on the content, the adolescent's individual characteristics, and the amount of time spent; it provides no per-user probability of harm- Extrait
“"Science demonstrates that social media use, in and of itself, is not sufficient to be helpful or harmful to young people." ”
- Données source de
- 2023-05-09
- Consulté le
- 2026-04-18 · copie archivée
- Calcul
- The APA health advisory is included as a second authoritative institutional statement. Like the Surgeon General's Advisory, it summarises the correlational literature without producing a probability figure. Its key contribution to this entry is the explicit statement that social media use "in and of itself" is insufficient to cause harm — effects depend on content type, individual vulnerability, and usage patterns. This supports the no_reliable_estimate framing: there is no single population-level probability that applies to "a teenager using social media."
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[4] Wall Street Journal (Wells, Horwitz, Seetharaman 2021) — Facebook Knows Instagram Is Toxic for Teen Girls, Company Documents Show
Facebook Knows Instagram Is Toxic for Teen Girls, Company Documents Show- Statistique
Internal Facebook research found that 32% of teen girls surveyed said Instagram made them feel worse about their body when they already felt bad about it; the research also found Instagram was cited as a contributor to anxiety and depression in a subset of teen users- Extrait
“"Thirty-two percent of teen girls said that when they felt bad about their bodies, Instagram made them feel worse." ”
- Données source de
- 2021-09-14
- Consulté le
- 2026-04-18 · copie archivée
- Calcul
- The WSJ Facebook Files series leaked internal Instagram research that became the public catalyst for legislative and regulatory action. The "32% of teen girls" figure is widely cited but refers to a specific question — "when you already feel bad about your body, does Instagram make it worse?" — not to a base rate of developing a clinical condition. The leaked research used convenience-sampled internal surveys, not population-representative methods, and "felt worse" is a subjective self-report, not a clinical diagnosis of serious psychological harm. Included because it drove the public perception shift, not because it anchors a probability.
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[5] Journal of Child Psychology and Psychiatry (Odgers & Jensen 2020) — Annual Research Review: Adolescent mental health in the digital age: facts, fears, and future directions
Annual Research Review: Adolescent mental health in the digital age: facts, fears, and future directions- Statistique
Synthesising six prior reviews/meta-analyses plus large-scale preregistered cohort and momentary-assessment studies, the review finds the link between digital technology use and adolescent mental health to be a mix of conflicting small positive, negative, and null associations (e.g. Huang 2017 meta-analysis r = −0.07 overall, depression r ≈ −0.11; McCrae 2017 r = 0.13), with no support for causal claims at the population level- Extrait
“"At present, narrative reviews and meta-analytic work do not support causal claims, or even strong and consistent correlational patterns, linking adolescents' digital technology usage with mental health problems." ”
- Données source de
- 2020-01-17
- Consulté le
- 2026-04-18 · copie archivée
- Calcul
- Odgers & Jensen 2020 (J Child Psychol Psychiatry Annual Research Review) synthesises three evidence streams: narrative reviews and meta-analyses (2014-2019), large-scale preregistered cohort studies, and intensive longitudinal / ecological-momentary-assessment studies. Across them the reported associations are small and inconsistent in direction — the Huang (2017) meta-analysis (N = 19,652) found a mean SNS-well-being correlation of r = −0.07 (depression r ≈ −0.11), and the McCrae (2017) meta-analysis found r = 0.13 for depressive symptoms. The review's key contribution to this entry is its conclusion that the evidence base does not support causal claims, "or even strong and consistent correlational patterns," and does not warrant the widespread panic — while the outcome measures remain continuous well-being and symptom scales, not binary harm thresholds. (Earlier drafts of this entry mis-cited this review under a Clinical Psychological Science DOI that in fact resolves to Vuorre & Przybylski 2023, "Global Well-Being and Mental Health in the Internet Age" — a separate paper; the identifier was corrected to the real Odgers & Jensen 2020 DOI 10.1111/jcpp.13190 in 2026.)
- Indépendance
- Independent review drawing on a broader evidence base than Orben & Przybylski 2019, including six prior systematic reviews/meta-analyses, large-scale preregistered cohort studies (e.g. Understanding Society, N = 12,672), and diary/EMA designs.
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[6] Common Sense Media (2025) — Talk, Trust, and Trade-Offs: How and Why Teens Use AI Companions
Talk, Trust, and Trade-Offs: How and Why Teens Use AI Companions- Statistique
In a nationally representative survey of 1,060 US teens aged 13-17 (April-May 2025), nearly three in four teens (72%) had used an AI companion at least once and roughly half were regular users; the figure is an adoption rate, not a rate of resulting psychological harm- Extrait
“"Our new research reveals that nearly three in four teens have used AI companions, and half use them regularly." ”
- Données source de
- 2025-07-16
- Consulté le
- 2026-06-14 · copie archivée
- Calcul
- Added 2026-06-14 to document AI companion chatbots as a distinct emerging teen-harm vector separate from feed-based social media. Common Sense Media's nationally representative survey establishes that the exposure is now mainstream (72% of teens have tried one; ~half are regular users). It is cited strictly as an adoption-prevalence figure: the survey measures how many teens use companion bots, not how many are harmed by them. No native or normalized probability is derived because the entry remains no_reliable_estimate — surveys report adoption, not crisis incidence.
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[7] UNICEF (2026) — 'Deepfake abuse is abuse' — Statement by UNICEF on AI-generated sexualised images of children
'Deepfake abuse is abuse' — Statement by UNICEF on AI-generated sexualised images of children- Statistique
In a UNICEF, ECPAT and INTERPOL study across 11 countries (Disrupting Harm Phase 2, ~1,000 internet-using children aged 12-17 surveyed per country), at least 1.2 million children disclosed having had their images manipulated into sexually explicit deepfakes in the past year; in some countries this represents 1 in 25 children- Extrait
“"In a UNICEF, ECPAT and INTERPOL study across 11 countries, at least 1.2 million children disclosed having had their images manipulated into sexually explicit deepfakes in the past year. In some countries, this represents 1 in 25 children — the equivalent of one child in a typical classroom." ”
- Données source de
- 2026-02-04
- Consulté le
- 2026-06-14 · copie archivée
- Calcul
- Added 2026-06-14 to ground the AI-synthetic-media caveat. The original change brief attributed this 1.2-million figure to Thorn; that attribution could not be verified. The figure is actually from the UNICEF/ECPAT/INTERPOL Disrupting Harm Phase 2 study, cited here from the verbatim UNICEF statement. It is a cross-national exposure-disclosure rate (children reporting their images were manipulated into sexual deepfakes), not a per-user probability of psychological harm, so it does not change the no_reliable_estimate status. It documents that generative-AI synthetic media is a victimisation channel distinct from, and sometimes embedded within, social-media platforms.