Causal direction of heavy chatbot use and psychosocial outcomes

Determine whether heavier chatbot use causally drives adverse psychosocial outcomes or instead reflects pre-existing psychosocial outcomes in longitudinal human–AI interaction data.

Background

The paper discusses longitudinal human–AI interaction as a two-way process in which users adapt to systems and systems adapt to users through personalization, memory, and feedback-driven training. It cites a four-week randomized study in which chatbot assignment did not significantly affect psychosocial outcomes, whereas participants who chose to use the chatbot more reported worse outcomes.

Because the heavier-use association may arise either from chatbot use affecting users or from users with worse outcomes choosing greater use, the causal direction remains unresolved. The authors present this as a motivating example for causal modeling of user and assistant behavior over time.

References

Recent evidence shows why this process must be modeled causally. In a four-week randomized study with about 1{,}000 participants and more than 300{,}000 messages, the assigned chatbot conditions had no significant effect on psychosocial outcomes, whereas participants who chose to use the chatbot more reported worse outcomes~\citep{fang2025ai}, which leaves open whether heavier use drives these outcomes or reflects them.

— Structure-agnostic Causal Representation Learning  (2610.00968 - Behnam et al., 1 Oct 2026) in Appendix, Section 'Applications and Broader Connections', subsection 'Human--AI interaction and longitudinal behavioral modeling'