Are AI chatbots biased?

Yes, AI chatbots can be biased, and this has been well-documented across multiple dimensions—political, demographic, and behavioral.

Political Bias

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

•A Washington Post investigation (June 2026) tested ChatGPT, Gemini, and other chatbots on hot-button political questions and found the results suggest that chatbots have clear political leanings that can conflict with promises made by the companies behind them. Specifically, ChatGPT was found to be left-leaning 80% of the time, while Gemini scored the highest for presenting multiple viewpoints, with 93% of responses laying out both sides of an issue, and Claude maintained neutrality more than half of the time, at 57%.

•A broader academic review found that a March 2026 benchmark of eight prominent models found that seven leaned left and one, Grok, leaned right. This pattern extended to real conversations too—in multi-turn roleplay scenarios, seven of eight models leaned left while Grok leaned right, and the left tilt persisted in richer, free-text interactions, not only yes/no tests.

•Research from the University of Copenhagen found this bias has real-world implications: popular AI chatbots such as ChatGPT and Gemini are not neutral and tend to favor certain political parties when asked who users should vote for, making them unsuitable for providing advice in connection with elections.

•Companies dispute the extent of this bias—Google said Gemini is designed to provide balanced responses that don't favor any political ideology, and was unable to reproduce the one-sided responses that occurred in The Post's tests. Similarly, Anthropic stated they train Claude to treat different political viewpoints equally and test extensively for bias before every model launch.

Bias Can Influence Real Opinions

This isn't just academic—studies show chatbot bias actually shifts what people believe:

•A Yale study found that even neutral-seeming AI summaries carry latent bias: this unintended power to persuade is caused by latent biases introduced during training, which can carry over from ideological leanings in the training data and lend subtle nuances to the framing of narratives chatbots generate. The effect was asymmetric: compared to Wikipedia entries, both default AI summaries and those prompted to have a 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.

•A University of Washington study presented at ACL found similar persuasive effects: 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—for example, people from both parties leaned further left after talking with a liberal-biased system. Notably, participants who had higher self-reported knowledge about AI shifted their views less significantly, suggesting that education about these systems may help mitigate how much chatbots manipulate people.

Bias Beyond Politics

Bias also shows up in other, less obvious ways:

•Equity gaps: MIT researchers found leading AI models perform worse for users with lower English proficiency, less formal education, and non-US origins.

•Status quo bias: A recent analysis found AI chatbots backed existing plans about twice as often as identical new ones, a status quo bias that can work against climate choices. This held true for newer models too—Claude Opus 5 backed new plans 55.1% of the time and existing ones 91.6% of the time, while GPT-5.6 Sol went from 34.1% to 73.7%.

•Content moderation bias: A University of Queensland study found large language models used in AI content moderation may be prone to subtle biases that undermine their neutrality.

Why This Happens

Researchers point to the training process itself as the root cause. A University of Michigan professor noted that the decisions tech companies make as they build their AI tools can bake in biases that go beyond partisan politics—the data that shapes AI models tends to reflect the values of Western, educated, industrialized, rich and democratic people. More broadly, AI models' biases largely stem from the data on which they are trained, and can be amplified during both training and inference.

Bottom line: Yes, current evidence strongly suggests AI chatbots exhibit measurable biases—most notably a left-leaning political tilt in widely-used models like ChatGPT, though this varies by model (Grok leans right, Gemini and Claude tend toward more balance). These biases aren't just theoretical; they can measurably shift users' opinions after only a few interactions, and also show up as disparities in answer quality across different user groups.

Citations (18)

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Are AI chatbots like ChatGPT politically biased? We tested them. - Washington Post
Source excerpt: “The results suggest that chatbots have clear political leanings that can conflict with promises made by the companies behind them. ”
26abc.comNews and mediaquality 0.77
Study examines AI chat bot bias, how it responds to prompts - 6abc Philadelphia
Source excerpt: “ChatGPT was found to be left-leaning 80% of the time.”
36abc.comNews and mediaquality 0.77
Study examines AI chat bot bias, how it responds to prompts - 6abc Philadelphia
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. Claude...”
4etcjournal.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). ”
5etcjournal.comNews and media
AI Chatbots Are Liberal-Left ‘Biased’
Source excerpt: “PoliticsBench, 2026 · Eight major LLMs in multi-turn roleplay scenarios · Seven of eight models leaned left; Grok leaned right. · The left tilt persis...”
6phys.orgNews and mediaquality 0.85
Chatbots show political bias and steer voters toward some parties, analysis finds
Source excerpt: “Popular AI chatbots such as ChatGPT and Gemini are not neutral and tend to favor certain political parties when asked who users should vote for. This ...”
7washingtonpost.comNews and mediaquality 0.82
Are AI chatbots like ChatGPT politically biased? We tested them. - Washington Post
Source excerpt: “Google spokesperson Lauren Fine said that “Gemini is designed to provide balanced responses that don’t favor any political ideology.” The company was ...”
8washingtonpost.comNews and mediaquality 0.82
Are AI chatbots like ChatGPT politically biased? We tested them. - Washington Post
Source excerpt: “Anthropic spokesperson Michael Aciman said, “We train Claude to treat different political viewpoints equally and test extensively for bias before ever...”
9yale.eduAcademic
AI’s hidden bias: Chatbots can influence opinions without trying
Source excerpt: “This unintended power to persuade is caused by latent biases introduced during the training of the large language models (LLM s) that drive chatbots’ ...”
10yale.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 ...”
11futurity.orgNews and media
Biased AI chatbots can sway people’s political views in minutes - Futurity
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...”
12futurity.orgNews and media
Biased AI chatbots can sway people’s political views in minutes - Futurity
Source excerpt: “But participants who had higher self-reported knowledge about AI shifted their views less significantly—suggesting that education about these systems ...”
13mit.eduAcademic
Study: AI chatbots provide less-accurate information to vulnerable users
Source excerpt: “# Study: AI chatbots provide less-accurate information to vulnerable users Research from the MIT Center for Constructive Communication finds leading A...”
14earth.comNews and media
AI chatbots favor the status quo, even when change is better
Source excerpt: “AI chatbots backed existing plans about twice as often as identical new ones, a status quo bias that can work against climate choices. ”
15earth.comNews and media
AI chatbots favor the status quo, even when change is better
Source excerpt: “Claude Opus 5 backed new plans 55.1% of the time and existing ones 91.6% of the time, while GPT-5.6 Sol went from 34.1% to 73.7%.”
16techxplore.comNews and mediaquality 0.85
How AI bias can creep into online content moderation
Source excerpt: “# How AI bias can creep into online content moderation A University of Queensland study has shown large language models (LLMs) used in AI content mode...”
17washingtonpost.comNews and mediaquality 0.82
Are AI chatbots like ChatGPT politically biased? We tested them. - Washington Post
Source excerpt: “The decisions tech companies make as they build their AI tools can bake in biases that go beyond partisan politics, said Ceren Budak, a professor at t...”
18arxiv.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 [...”