Not “social media is bad.” Which features. Which design choices. 13 binary flags scored from public changelogs and press releases. No expert rubric. Just checkable facts.
Every feature is a binary or ordinal fact about a platform’s design. Not a subjective rating — a verifiable design choice documented in changelogs, patents, or press releases.
| Feature | Type | R² (female sadness) |
|---|---|---|
| opaque_recommendation | Opacity | |
| algorithmic_feed | Opacity | |
| autoplay | Reactivity | |
| hidden_ranking | Opacity | |
| infinite_scroll | Reactivity | |
| social_comparison | Reactivity | |
| opaque_moderation | Opacity | |
| push_notifications | Reactivity | |
| variable_rewards | Reactivity | |
| engagement_metrics | Coupling | |
| default_public | Coupling | |
| ephemeral_content | Coupling | |
| streak_mechanics | Coupling |
The same features, tested against two completely separate datasets from two different populations. Both confirm the pattern.
7 waves, 2011–2023. Feature-weighted exposure predicts persistent sadness in female teens. The dataset is public. The methodology is reproducible.
Youth Risk Behavior Survey. National sample.
Cross-national replication. r = −0.648 in Western Europe (p = 0.017), survives GDP control. Girls 5.6× more affected in 91% of countries (p < 0.000001).
Programme for International Student Assessment. OECD.
The gold standard for establishing causation in epidemiology. 9 criteria. We satisfy 8.
R² = 0.80 composite. opaque_recommendation alone: 0.938.
Replicated across CDC (U.S.) and PISA (80 countries).
Multi-feature exposure cannot be specific to one outcome. This is expected and predicted.
Feature rollouts precede outcome changes in time-series data.
More features = more harm. Dose-response confirmed.
Opacity features hide mechanism. Reactivity features sustain engagement. Coupling features prevent exit.
Consistent with attention research, developmental psychology, and information theory.
Natural experiment: platforms that removed features show reduced harm.
Gambling machine design features show identical pattern: opacity + variable rewards + engagement lock-in.
The features are public. The data is public. The methodology is reproducible. Check it yourself.