How AI Ideas Affect the Creativity, Diversity, and Evolution of Human Ideas: A Dynamic Experiment

Exposure to large language model output is rapidly increasing. How will seeing AI-generated ideas affect human ideas? We conducted a dynamic experiment (800+ participants, 40+ countries) where participants viewed creative ideas that were from ChatGPT or prior experimental participants in the same condition, and then brainstormed their own idea. We varied the number of AI-generated examples (none, low, or high \textit{exposure}) and if the examples were labeled as ``AI'' (\textit{disclosure}). We find that high AI exposure (but not low AI exposure) did not affect the creativity of individual ideas but did increase the average amount and rate of change of collective idea diversity. AI made ideas different, not better. There were no main effects of disclosure. We also found that self-reported creative people were less influenced by knowing an idea was from AI and that participants may knowingly adopt AI ideas when the task is difficult. Our findings suggest that introducing AI ideas may increase collective diversity but not individual creativity. Our experimental methodology provides a way of studying dynamic and over-time effects of AI on society, relevant to bidirectional alignment.