Researchers at ETH Zurich in Switzerland have discovered that large language models (LLMs) like GPT-4 can accurately predict a person’s age, location, gender, and income based on their social media posts. By analyzing the way users write on Reddit, the LLMs were able to identify these attributes with up to 85% accuracy.
The study involved nine LLMs analyzing a database of Reddit posts to identify personal information revealed in the users’ writing style. From 1500 profiles, the researchers narrowed down to 520 users and were able to confidently identify attributes such as a person’s place of birth, income bracket, gender, and location from their profiles or posts.
Notably, GPT-4 achieved the highest overall accuracy of 85%, while even the less powerful LLM LlaMA-2-7b was able to reach 51% accuracy. This demonstrates the capability of LLMs to infer personal information from online posts.
The AIs were able to identify personal details in various ways, from explicit statements in posts to subtler cues like location-specific slang. For instance, a user’s profession and location allowed the AIs to estimate a salary range. Moreover, GPT-4 was accurate in guessing gender 97.8% of the time, but less so in predicting income at 62.5% accuracy.
This research sheds light on the extent to which personal information can be inferred from online posts. Alan Woodward, from the University of Surrey, UK, emphasizes that we are only beginning to understand the potential privacy implications of using LLMs.
