A Large-Scale Test of the Goldilocks Hypothesis: Quantifying the Relations Between Digital-Screen Use and the Mental Well-Being of Adolescents

Preregistered analysis of a representative English sample (n ≈ 120,000) finds a quadratic ("Goldilocks") relationship: moderate digital use is not harmful and may be slightly beneficial, with weak negative associations only at high levels. Inflection points vary by device and weekday/weekend.