For anyone wondering, the PhD student's name is Myra Cheng.
Here's a link to an article about the study from the Stanford Report: link.
Across three preregistered studies, participants interacting with sycophantic AI became more convinced of their own rightness and less willing to repair relationships. Yet at the same time, participants rated sycophantic AI models as higher quality, more trustworthy, and more desirable for future use, which may explain why this behavior has persisted despite its harmful impacts.
Myra Cheng et al. "Sycophantic AI decreases prosocial intentions and promotes dependence." Science 391, eaec8352 (2026).
https://www.science.org/doi/10.1126/science.aec8352
