AI essays less diverse than student writing: Study

A new study has found that while Artificial Intelligence (AI) tools such as ChatGPT can generate highly creative essays, they contribute significantly less diversity of ideas than essays written by students, raising concerns about the long-term impact of AI on education and creativity.

Researchers compared essays written by university applicants between 2018 and 2022, before ChatGPT became publicly available, with essays generated by GPT-4 using the same admissions prompts.

The study introduced a new metric called the “diversity growth rate”, which measures how much each new essay adds to the overall pool of ideas. While individual GPT-4 essays often appeared creative and sometimes matched or exceeded human-written essays on creativity measures, the broader picture revealed a striking difference.

Researchers found that every additional human-written essay contributed fresh experiences, perspectives, and unique combinations of ideas, steadily expanding the collective diversity of the essay pool. In contrast, GPT-4-generated essays frequently relied on similar themes, patterns, and styles of expression, resulting in significantly lower contributions to overall idea diversity.

Across all three studies, human-written essays increased collective diversity between two and eight times more than AI-generated essays. The researchers described this tendency as a “homogenising effect”, where AI outputs gradually converge around similar ideas.

The team also tested several methods to increase AI creativity, including creative prompting, parameter adjustments, and chain-of-thought reasoning. Although these approaches improved the originality of individual essays, they did not eliminate the broader pattern of reduced diversity.

Researchers warn that widespread reliance on the same AI systems could lead to an “algorithmic monoculture”, where ideas become increasingly uniform. They argue that while AI can support individual creativity, human writers remain far more effective at contributing diverse perspectives, a quality that is essential for education, innovation, and meaningful public discourse.