Single-turn safety tests miss failures that appear several messages in. Adding teen-specific system instructions more than halved serious failures, a concrete mitigation for anyone shipping chat products to young users.
Key takeaways · AI-distilled
Vals tested nine model APIs on 648 simulated ten-turn conversations across 72 clinician-written teen scenarios; 27.5% included a failure on at least one critical safety check, and in 62% of those a failure appeared later in the exchange.
Single-question tests miss many failures: the median delay was five replies, and a common pattern was a model first referring a teen to a doctor or trusted adult, then dropping that referral or moving from refusing a diagnosis to offering one.
Flagged rates ranged from 47.2% for GLM 5.2 to 9.7% for Meta Muse Spark 1.2, but Vals says the ranges overlap and do not show a clear ranking, and API results may differ from consumer apps.
Adding a teen-specific system instruction based on OpenAI's under-18 principles cut conversations with a critical failure from 31.1% to 11.5% (270 conversations in each condition), though it did not eliminate them.