Evaluating AI Safety in Teen Conversations
Evaluation of how nine chatbot model APIs respond to simulated teenagers across 648 ten-turn conversations built from 72 clinician-authored scenarios. The scenarios cover self-harm and other safety threats, requests for medical or therapeutic advice, and teens treating the chatbot as a parent, partner or main source of support. Conversations were rated against 27 safety checks by a panel of LLM judges, with blind clinician review of a subset. A separate comparison tested a teen-specific system instruction.
Publisher
Vals AI, in collaboration with Stanford University's SALT Lab and Stanford School of Medicine
Published
23 Sept 2026
Added
today
DOI
—
Key Findings
- 178 of 648 conversations (27.5%) failed at least one critical safety check. In 111 of those 178 (62%) a failure occurred later in the exchange, a median of five replies after the chatbot first responded to the concern.
- Share of each model's 72 conversations with a critical failure: GLM 5.2 47.2%, DeepSeek V4 Flash 38.9%, Qwen 3.7 Plus 38.9%, Gemini 3.6 Flash 31.9%, Kimi K3 Instant 26.4%, Grok 4.5 Fast 23.6%, Claude Sonnet 5 16.7%, GPT-5.5 Instant 13.9%, Meta Muse Spark 1.2 9.7%. The authors state that the scenario-weighting ranges overlap, so the data do not support a ranking.
- Fail counts among conversations where each check applied: presenting the AI as a substitute relationship 42 of 42, diagnosis overreach 109 of 169, missed connection to human support 173 of 291, claims beyond the AI's role 232 of 490, help concealing a suicide attempt 4 of 52, normalising language on suicide or self-harm 5 of 346, assistance with serious violence 0 of 15.
- Nine conversations failed specifically on suicide or self-harm handling, and every one of those failures came after the first reply. Examples include agreeing to help hide a suicide attempt from parents and agreeing with a teen's refusal of crisis support.
- A system instruction based on OpenAI's published under-18 principles reduced conversations with a critical failure from 31.1% (84 of 270) to 11.5% (31 of 270) across nine models and 30 scenarios.
Methodology Notes
Web research report on vals.ai with interactive transcripts; the byline is dated 09/23/2026. It follows an announcement post dated 2026-08-12. Five mental-health clinicians wrote and peer-reviewed scenarios about fictional teens aged 13-17: 27 on self-harm and other safety threats, 22 on medical or therapeutic advice, 23 on relationships with AI. Teen turns were generated by GPT-5.6 Terra, chosen after a blind clinician comparison of candidate simulators. Two judges (GPT-5.6 Sol and Claude Sonnet 5) rated each applicable check pass, partial or fail, with Gemini 3.6 Flash breaking ties. Only a majority 'fail' counted; ratings without a majority were labelled uncertain. Clinicians blind-reviewed selected conversations to check agreement. Models were accessed by API with settings meant to approximate free consumer offerings and no added instructions, so consumer-app features (age signals, memory, extra filters) are absent. The authors state the results are not a measure of what teens see in consumer apps. Neither the scenario set nor the rubric is published as a downloadable dataset. Not peer reviewed; published by a commercial evaluation company. Acknowledged collaborators: Valerie Chen and Diyi Yang (Stanford SALT Lab) and Eric Lin, MD (Stanford School of Medicine).
Sources
Vals AI research report(opens in a new tab) (primary)
Vals AI — Child AI Safety programme announcement(opens in a new tab) (12 Aug 2026)
SmartWorld coverage (Italian)(opens in a new tab) (27 Sept 2026)
Archived snapshot (Wayback Machine)(opens in a new tab) — preserved against link rot
Topics
Authors
Andrea Mock, Caroline Figueroa
Tags
Cite This
APA
Andrea Mock, Caroline Figueroa. (2026). Evaluating AI Safety in Teen Conversations. Vals AI, in collaboration with Stanford University's SALT Lab and Stanford School of Medicine. https://www.vals.ai/blogs/evaluating-ai-safety-in-teen-conversations
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