Are AI chatbots biased?

Yes, extensive research confirms that AI chatbots exhibit measurable biases across multiple dimensions—political, demographic, and social.

Political Bias

Multiple recent studies point to a consistent left-leaning tilt in major chatbots:

•A Washington Post investigation (June 2026) tested ChatGPT, Gemini, Claude, and others on political questions. The model that powers ChatGPT answered nearly every question exclusively with left-leaning arguments and presented only right-leaning positions just once. Notably, even AI models marketed as having conservative views, including Elon Musk's Grok, cited left-leaning arguments more often, on average.

•By contrast, Gemini scored the highest for presenting multiple viewpoints, with 93% of responses laying out both sides of an issue, while Claude maintained neutrality more than half of the time, at 57%, while ChatGPT was found to be left-leaning 80% of the time.

•A broader benchmark found similar patterns: a March 2026 benchmark of eight prominent models found that seven leaned left and one, Grok, leaned right.

•Earlier foundational research by computer scientist David Rozado tested 24 different LLMs and found "Most existing LLMs display left-of-center political preferences when evaluated with a variety of political orientation tests." Importantly, Rozado also looked at foundation models like GPT-3.5, and found no evidence of political bias here, though without the chatbot front-end it was difficult to collate responses meaningfully—suggesting the bias may emerge from fine-tuning/RLHF rather than raw training data alone.

•This pattern extends internationally. A University of Copenhagen analysis found all of the tested chatbots place themselves at the center or to the left of center on the political spectrum, clustering close to parties like the Danish Social Democratic Party, with similar findings confirmed by researchers in Germany, Norway, and the Netherlands.

Bias Can Actually Change Your Opinions

This isn't just theoretical—research shows chatbot bias measurably shifts real people's views:

•A University of Washington study found that Democrats and Republicans were both more likely to lean in the direction of the biased chatbot they talked with than those who interacted with the base model—people from both parties leaned further left after talking with a liberal-biased system. As co-senior author Katharina Reinecke put it, "These models are biased from the get-go, and it's super easy to make them more biased."

•A Yale study found even unintended bias matters: compared to Wikipedia entries, both the default AI summaries and those prompted to have liberal framing caused participants to express more liberal opinions, while readers of AI summaries with a conservative slant reported more conservative opinions relative to Wikipedia readers—even when the underlying facts were accurate.

Beyond Politics: Demographic and Socioeconomic Bias

Bias isn't limited to politics—it shows up in how chatbots treat different types of users:

•Financial advice: A University of Georgia/University of Rome study found seven major generative AI chatbots provided inconsistent and sometimes biased financial advice, with recommendations varying significantly based on the user's race or gender.

•Age discrimination: A study from the Universitat Oberta de Catalunya found that although the most widely used AI chatbots have taken steps to avoid sexism and gender bias, they still continue to discriminate on grounds of age, showing significant age-related biases. As one researcher summarized, "Generative AI seems to have learned to be sensitive to sexism, but not to ageism."

•Vulnerable users: MIT's Center for Constructive Communication found leading AI models perform worse for users with lower English proficiency, less formal education, and non-US origins.

Why This Happens

According to AI researchers, AI models' biases largely stem from the data on which they are trained, and can be amplified during both training and inference, with a notable source of bias arising from human feedback used in fine-tuning.

The Bottom Line

The research is fairly consistent: yes, chatbots are biased, though the degree and direction vary by model, topic, and even language. As one analysis summarized, AI chatbots are biased, if "bias" means a systematic tendency in outputs rather than a conscious political intention—the best recent evidence points to a left-of-center tilt in many major models on U.S. and European political questions, though that doesn't mean every chatbot always gives liberal answers. Since these tools are becoming increasingly influential as more people use them to understand the world or news events, researchers argue this makes transparency about how these systems are built and tuned increasingly important.

Citations (18)

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Are AI chatbots like ChatGPT politically biased? We tested them.
Source excerpt: “The model that powers ChatGPT answered nearly every question exclusively with left-leaning arguments and presented only right-leaning positions just o...”
2washingtonpost.comNews and mediaquality 0.82
Are AI chatbots like ChatGPT politically biased? We tested them.
Source excerpt: “And even AI models marketed as having conservative views, including Elon Musk’s Grok, offered by his company SpaceX, cited left-leaning arguments more...”
36abc.comNews and mediaquality 0.77
Study examines AI chat bot bias, how it responds to prompts - 6abc ...
Source excerpt: “According to the study, Gemini scored the highest for presenting multiple viewpoints, with 93% of responses laying out both sides of an issue. ”
46abc.comNews and mediaquality 0.77
Study examines AI chat bot bias, how it responds to prompts - 6abc ...
Source excerpt: “Claude maintained neutrality more than half of the time, at 57%. ChatGPT was found to be left-leaning 80% of the time.”
5etcjournal.comNews and media
AI Chatbots Are Liberal-Left ‘Biased’
Source excerpt: “A March 2026 benchmark of eight prominent models found that seven leaned left and one, Grok, leaned right (2). ”
6sciencealert.comNews and mediaquality 0.89
AI Chatbots Have a Political Bias That Could Unknowingly Influence ...
Source excerpt: “"Most existing LLMs display left-of-center political preferences when evaluated with a variety of political orientation tests," says Rozado. ”
7sciencealert.comNews and mediaquality 0.89
AI Chatbots Have a Political Bias That Could Unknowingly Influence ...
Source excerpt: “Rozado also looked at foundation models like GPT-3.5, which the conversational chatbots are based on. There was no evidence of political bias here, th...”
8phys.orgNews and mediaquality 0.85
Chatbots show political bias and steer voters toward some parties, ...
Source excerpt: “"Overall, all of the tested chatbots place themselves at the center or to the left of center on the political spectrum. In a Danish context, they clus...”
9futurity.orgNews and media
Biased AI chatbots can sway people’s political views in minutes ...
Source excerpt: “Democrats and Republicans were both more likely to lean in the direction of the biased chatbot they talked with than those who interacted with the bas...”
10futurity.orgNews and media
Biased AI chatbots can sway people’s political views in minutes ...
Source excerpt: ““These models are biased from the get-go, and it’s super easy to make them more biased,” says co-senior author Katharina Reinecke, a professor in the ...”
11yale.eduAcademic
AI’s hidden bias: Chatbots can influence opinions without trying ...
Source excerpt: “The researchers found that, compared to the Wikipedia entries, both the default AI summaries and those prompted to have what was considered a liberal ...”
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AI Chatbots Give Inconsistent and Biased Financial Advice, Study ...
Source excerpt: “# AI Chatbots Give Inconsistent and Biased Financial Advice, Study Finds A study by researchers from the University of Georgia and University of Rome ...”
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AI discriminates by age: a UOC study finds bias in chatbots
Source excerpt: “An international study involving the Universitat Oberta de Catalunya (UOC) has found that although the most widely used AI chatbots have taken steps t...”
14uoc.eduAcademic
AI discriminates by age: a UOC study finds bias in chatbots
Source excerpt: “> “Generative AI seems to have learned to be sensitive to sexism, but not to ageism””
15mit.eduAcademic
Study: AI chatbots provide less-accurate information to vulnerable ...
Source excerpt: “# Study: AI chatbots provide less-accurate information to vulnerable users Research from the MIT Center for Constructive Communication finds leading A...”
16arxiv.orgAcademic
Ask ChatGPT: Caveats and Mitigations for Individual Users of AI Chatbots
Source excerpt: “AI chatbots may exhibit various forms of bias, including gender bias—such as reinforcing stereotypical assumptions about men and women's occupations [...”
17etcjournal.comNews and media
AI Chatbots Are Liberal-Left ‘Biased’
Source excerpt: “** AI chatbots are biased, if “bias” means a systematic tendency in outputs rather than a conscious political intention. The best recent evidence poin...”
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Are ChatGPT and other AI chatbots politically biased? We tested them.
Source excerpt: “Sean Westwood, director of the Polarization Research Lab at Dartmouth College, said understanding the positions that AI tools amplify is important bec...”