A new study by researchers at ETH Zurich has found that artificial intelligence can predict key personality traits by analyzing conversations people have with chatbots, raising fresh concerns about privacy and the growing amount of personal data shared online.
The research, published as a pre-print study, examined whether AI systems could identify psychological characteristics from user interactions with chat platforms such as ChatGPT. Researchers collected chat histories from 668 users in the United States and the United Kingdom who agreed to share their conversations for the project.
More than 62,000 chat exchanges were analyzed and grouped according to topic and communication style. Using this information, researchers trained an AI model to estimate whether users displayed traits linked to the “Big Five” personality categories commonly used in psychology: agreeableness, conscientiousness, emotional stability, extraversion, and openness.
Participants also completed standard psychological assessments so researchers could compare the AI’s predictions with established personality test results.
According to the study, the AI model identified some personality traits with accuracy levels reaching 61 percent. The system performed best when predicting agreeableness and emotional stability, while it struggled more with conscientiousness.
Researchers said the accuracy improved when the AI had access to longer conversation histories, suggesting that extensive chatbot use may reveal more about an individual’s personality over time.
The findings add to growing debate over how personal information shared with AI systems could be used in the future. While researchers said the immediate risks for individuals appear limited, they warned that large-scale collection of personality data could create broader concerns.
The study noted that such information could potentially be exploited in targeted advertising campaigns, political messaging, or disinformation efforts designed to influence specific groups of people.
Researchers also warned that users may not fully realize how much personal insight can be extracted from ordinary conversations with AI assistants. Topics people discuss, the language they use, and the emotional tone of messages can all provide clues about behavior and personality patterns.
The team said the results could help developers create stronger privacy protections for AI systems. One proposal involves building tools that automatically remove identifying or sensitive details from conversations before they are stored or analyzed.
As AI chatbots become increasingly common in workplaces, education, and daily life, the study is expected to fuel further discussion over how companies collect, store, and protect user data in rapidly expanding digital environments.