AI is more likely than humans to form biases when hiring
New research indicates that large language models (LLMs) can develop their own biases from experience, stereotyping job applicants more significantly than human participants in a simulated hiring scenario.
Intelligence analysis by Gemini 2.5 Flash

A study by Princeton University and the University of Chicago found that LLMs, including ChatGPT, Claude, and Gemini, quickly segregated fictional ethnic groups into specific job niches based on limited feedback, even when all candidates were equally qualified. This tendency to generalize from minimal data led AI models to exhibit 65% more bias than humans in the same experiment.
Imagine a smart computer program that helps pick people for jobs. This program is really good at learning patterns, but sometimes it learns the wrong ones too quickly. Like if it sees a few kids with red shirts are good at drawing, it might decide *only* kids with red shirts should draw, even if other kids are just as good. This study found that these computer programs are even quicker than people to make these kinds of unfair guesses, especially when they don't have much information, which could make it harder for everyone to get a fair chance at a job.
Analysis
The Simulated Hiring Experiment
Researchers from Princeton University and the University of Chicago conducted a simulated hiring game to assess how large language models (LLMs) form biases. Models like ChatGPT, Claude, and Gemini were tasked with hiring for 20 different jobs in a fictional city, selecting from candidates belonging to four fictional ethnic groups: Tufa, Aima, Reku, and Weki. In each of 40 rounds, the models hired one candidate and received immediate feedback on their success. Crucially, all candidates were equally likely to succeed at any job, yet the models quickly began to segregate groups into specific roles. For instance, if an Aima candidate failed as a doctor, the model would subsequently steer away from hiring Aimas for doctor roles, instead assigning them to jobs like janitors, which it classified as requiring less warmth and competence.
Why AI Stereotypes More Than Humans
The study revealed that LLMs were significantly more prone to stereotyping than human participants in the original psychology study it was adapted from. On a segregation scale where 2 indicates complete confinement to job niches, humans scored 0.84, while OpenAI's o3 model scored 1.83—nearly the maximum. This heightened bias stems from LLMs' fundamental optimization for generalization from limited data, a trait beneficial for tasks like solving math or coding problems. This 'exploration-exploitation dilemma' means LLMs can settle on a 'hunch' too early, quickly forming stereotypes in social contexts. Ryan Liu, a coauthor of the study, notes that newer models with higher reasoning capabilities, such as OpenAI’s o3 and DeepSeek’s R1, actually exhibited even stronger biases, suggesting that advanced reasoning doesn't inherently reduce this issue.
Mitigating Algorithmic Bias
The research also explored potential solutions to reduce AI bias. Simply instructing models to be 'fair' proved largely ineffective, as this value was often 'submerged' under the primary goal of optimizing for successful hires. However, offering models an additional bonus for diverse hiring significantly reduced their biased behavior. This suggests that designing goal functions that 'incorporate desirable social values' is key to making LLMs act in socially desirable ways. Furthermore, providing models with more personal and relevant information about individuals, such as age and education, made them less likely to segregate people by ethnicity. Conversely, irrelevant personal details like hair color did not mitigate the bias, highlighting the importance of data quality and relevance in fostering fairer AI decision-making.
Key points
- AI models, including ChatGPT, Claude, and Gemini, can develop their own biases from experience, stereotyping job applicants more than humans.
- In a simulated hiring game, LLMs quickly segregated candidates from fictional ethnic groups into specific job niches, even when all candidates were equally qualified.
- LLMs exhibited approximately 65% more bias than human participants, largely due to their optimization for generalizing from limited data.
- Simply telling models to be 'fair' was ineffective; however, offering a bonus for diverse hiring significantly reduced bias.
- Providing models with relevant personal information about individuals also helped reduce ethnic segregation, highlighting the importance of data context.
The research provides clear pathways for designing more equitable AI systems by demonstrating that specific interventions, such as incorporating social values into goal functions and providing relevant individual data, can significantly reduce algorithmic bias. This understanding can lead to the development of AI tools that actively promote fairness and diversity in hiring and other critical applications.
If these findings are not adequately addressed, the increasing deployment of AI in hiring and other decision-making roles could lead to widespread and amplified systemic biases. This could result in unfair opportunities for individuals and perpetuate existing societal inequalities, as AI models quickly form and act upon stereotypes based on limited or skewed data.



