Australia introduced a world-first law banning children under 16 from accessing social media platforms. The Online Safety Amendment (Social Media Minimum Age), which took effect in December 2025, requires providers of social media platforms to take reasonable steps to prevent Australians under 16 from having accounts, or face civil penalties. Similarly, the UK government has announced that from Spring 2027 children under 16 will be prohibited from accessing certain social media platforms. Several other countries, including Denmark, France, Germany, Indonesia, Norway, and Spain, have introduced or adopted similar approaches. If different jurisdictions and platforms are setting different age thresholds, does neuroscience actually support a single fixed age?

Based on neuroscience, there is no single age that should be considered safe or unsafe for children’s exposure to social media platforms. Brain development and maturation are continuous, individualized, and multidimensional. However, legal and platform age thresholds vary across jurisdictions, generally ranging from 13 to 18 years old. The growing number of these measures reflects increasing fragmentation and the urgency of addressing online child safety. Cultural differences regarding childhood autonomy, parental authority, and online privacy further complicate efforts to define the right age.  Instead of establishing fixed age thresholds, online child safety may be better served by regulations that target platform designs and variable reward systems in ways calibrated to users’ developmental stages.

The “Right” Age?

Age assurance approaches vary across countries. In particular, the European Union member states reflect the flexibility provided under the General Data Protection Regulation (GDPR). The GDPR sets 16 as the age for a child’s independent consent for information-society services, while allowing member states to lower the threshold to 13.[1] In April 2026, the European Union further strengthened its approach by announcing the deployment of an age verification app enabling users to verify their age when accessing online services.[2] This approach introduces age-verification infrastructure rather than setting new legal thresholds. Moreover, the United States has adopted a threshold for children’s personal data processing. The Children’s Online Privacy Protection Act of 1998 (COPPA) requires covered online services to obtain verifiable parental consent before collecting, using, or disclosing personal information from children under 13.[3] While such requirements are absent at the federal level, age assurance and verification thresholds are implemented under state laws.[4]

Social media platforms’ policies are shaped by this regulatory fragmentation. Major social media platforms, such as Facebook,[5] Instagram,[6] TikTok,[7] and X,[8] explicitly adhere to a 13-year-old threshold, prohibiting users below this age from creating accounts or redirecting them to age-appropriate experiences. However, varied age thresholds have been adopted for specific policies across platforms, such as restricting specific features like direct messaging or content access settings. The appeal of the fixed thresholds is that they are simple to enforce and provide clear expectations for users, parents, platforms, and regulators. These measures raise a question: does neuroscience actually support a single age cutoff?

What Neuroscience Tells Us and Why It Does Not Give A Number

The limbic system governs emotional processing and rewards. This system shows increased sensitivity during puberty because hormonal changes increase an individual’s responsiveness to rewards and social  feedback. In contrast, the prefrontal cortex is responsible for impulse control, planning, and risk assessment, and is one of the last parts of the brain to fully develop. While the full maturity of the prefrontal cortex is estimated to occur by the mid-twenties, approximately 25 years old,[9] this is not absolute. Brain development varies across different people. Some individuals reach a plateau earlier, while others experience maturation that extends even further.[10]

The fact that emotional responsiveness and sensation-seeking develop earlier than self-regulation creates a developmental mismatch. While this imbalance between the dual systems has become a dominant framework for understanding adolescent risk-taking, the model has been contested as an oversimplification. The same child may be cognitively competent, but still psychosocially vulnerable. Although this imbalance is a general pattern, it does not occur at a specific age. Brain development is better understood as a gradient rather than a threshold. Different cognitive and psychosocial capacities emerge at different times and vary significantly across children. Therefore, a single age threshold is both over- and under-inclusive. It restricts children who can understand and engage with specific features before the specified age, while failing to protect other children who are not ready. Neuroscience offers developmental patterns, but it does not directly determine the appropriate regulatory thresholds, which remain policy choices.

How Platform Design Interacts with Developing Brains

Platform designs may influence adolescent behavior and engagement patterns during brain development. Features such as personalized content, infinite scroll, and unpredictable notifications (such as likes, shares, or comments) may function as variable-ratio reward mechanisms. These features are associated with dopamine-related reward responses and may increase engagement, potentially contributing to more compulsive use patterns.[11] Young users whose prefrontal cortex is still developing could be more susceptible to peer influence. They may experience heightened sensitivity to social approval and rejection.[12]

While there is no clear age threshold, neuroscience could explain that different risks align with  different brain developmental timelines. The feature-based approach suggests a shift from one-size-fits-all age thresholds to regulations that tailor platform features to users’ developmental stages. By tailoring platform features to users’ developmental stages, this approach addresses the actual sources of harm. Although more complex to implement than a single age cutoff, it may better align protections with the risks children face at different stages.

Some social media platforms have moved toward this approach. For example, TikTok sets a default daily screen time of 60 minutes for users aged 13-17.[13] It disables push notifications from 9 PM for users aged 13-15, and 10 PM for those aged 16-17.[14] Similarly, Facebook has implemented the Facebook Teen Accounts for users aged 13-17, automatically applying more protective settings and sleep mode, as well as a daily limit reminder by default.[15] Instagram restricts direct messaging between users identified as teens and unknown users over 18.[16] These examples suggest that platforms already operate on a gradient model in practice.

Beyond these default age-related features, many platforms allow parents or guardians to set up features appropriately for their children. Their developmental needs may be best understood by their parents or guardians. For example, YouTube’s Kids account allows signed-in parents to select a content experience for their children from preschool (ages 4 and under), younger (ages 5-8), older (ages 9-12), or a customized selection where parents approve content themselves.[17] These measures also reflect broader issues about platform responsibility. In the United States, recent product-liability verdicts have increased attention to claims involving allegedly addictive software design.

Moving Forward & Open Questions

There is no single right age. But there are design features that may be more or less appropriate at different developmental stages. Neuroscience helps explain this developmental gap. Specifically, reward systems and platform features may affect children differently. However, the precise thresholds, such as how many notifications or how much screen time trigger harm remain unclear.

Some social media platforms have implemented age-tiered approaches, but broader regulatory development is needed. Some level of age assurance remains necessary. It is still important for platforms to know a user’s approximate age in order to apply age-tiered protection effectively. However, a regulatory framework should treat age as a gradient, not a single gatekeeping threshold. Requirements should move beyond relying exclusively on fixed age thresholds and be built around risk- and design-based models. Platforms should still be required to assess risks and adapt their features to users’ age-related and developmental needs.

A feature-level approach is not perfect, but it is more closely aligned with how risk actually occurs. While more complex to enforce than a single age cutoff, this approach better balances the goal of mitigating online harms to children while preserving their access to social media. At the same time, the law should limit harms arising from age assurance or verification tools themselves, such as data privacy risks. Looking ahead, deeper collaboration between neuroscientists, platforms, and regulators will be necessary to refine this approach.

References

[1] EU GDPR Article 8, Conditions Applicable to Child’s Consent in Relation to Information Society Services.

[2] European Commission, European Age Verification App to Keep Children Safe Online, April 2026, https://commission.europa.eu/news-and-media/news/european-age-verification-app-keep-children-safe-online-2026-04-15_en.

[3] § 312.2 Definitions (defining “child” as an individual under the age of 13) and § 312.5 Parental Consent.

[4] Texas’s Securing Children Online Through Parental Empowerment (SCOPE) Act requires a digital service provider to register the age of the user, and users under 18 years old must obtain parental or guardian consent before creating an account; see also, Free Speech Coalition v. Paxton.

[5] Meta, Terms of Services, version 1 January 2025, https://www.facebook.com/terms/.

[6] Instagram, Terms of Use, https://help.instagram.com/termsofuse.

[7] TikTok, Terms of Services, version 22 January 2026, https://www.tiktok.com/legal/page/us/terms-of-service/en.

[8] X, Terms of Services, version 17 December 2025, https://x.com/en/tos.

[9] Mariam Arain et al., Maturation of the Adolescent Brain (2013), https://pmc.ncbi.nlm.nih.gov/articles/PMC3621648/.

[10] Leah H. Somerville, Searching for Signatures of Brain Maturity: What Are We Searching For? (2016), https://www.sciencedirect.com/science/article/pii/S0896627316308091; see also, Kathryn L Mills et al., Inter-Individual Variability in Structural Brain Development from Late Childhood to Young Adulthood (2021),https://pmc.ncbi.nlm.nih.gov/articles/PMC8489572/.

[11] Jiangsong Wang and Shen Wang, The Emotional Reinforcement Mechanism of and Phased Intervention Strategies for Social Media Addiction (2025),  https://pubmed.ncbi.nlm.nih.gov/40426443/.

[12] Eveline A. Crone and Elly A. Konjin, Media Use and Brain Development During Adolescence (2018),https://www.nature.com/articles/s41467-018-03126-x; see also, Patrik Wikman et al., Brain Responses to Peer Feedback in Social Media Are Modulated by Valence in Late Adolescence (2022), https://pubmed.ncbi.nlm.nih.gov/35706832/.

[13] TikTok, Guardian’s Guide, https://www.tiktok.com/safety/en/tools-and-guides/guardians-guide.

[14] Id.

[15] Facebook, Help Centre, About Facebook Teen Accounts, https://www.facebook.com/help/1105851604342488.

[16] Instagram, Help Center, About Instagram Teen Privacy and Safety Settings, https://help.instagram.com/3237561506542117.

[17] YouTube, For Families Help, Help Center, Create a YouTube Kids Profile, https://support.google.com/youtubekids/answer/7554914?hl=en.