openai (gpt-5-nano-2025-08-07) · contradicted · 92%

The claim that humans 'only use exactly 10% of their brain' is a persistent myth; contemporary neuroscience shows widespread brain activity and utilization across regions, with no evidence for a fixed 90% unused capacity.

Key points: Neuroimaging reveals activity across most brain regions during tasks and at rest. | There is no credible evidence supporting that 90% of the brain is permanently inactive. | The '10% myth' has multiple historical origins and is debunked by neuroscience literature. | Brain energy use is high; however, functionality depends on dynamic network activity rather than unused capacity.

anthropic (claude-haiku-4-5-20251001) · contradicted · 98%

The '10% brain myth' is a persistent misconception that has been thoroughly debunked by neuroscience. Research demonstrates that humans use virtually all parts of their brain, and most of the brain is almost always active.

Key points: Brain imaging studies (fMRI, PET scans) show that even during sleep, all areas of the brain show some level of activity | Neuroplasticity studies demonstrate that the brain continuously reorganizes and utilizes different regions based on learning and experience | Damage to many brain areas results in significant functional impairment, indicating those regions are actively used | The average person uses approximately 100% of their brain over the course of a day | This myth likely originated from misquotations of early 20th-century psychologists like William James, but was distorted over time

Limitations: At any given moment, not all brain regions are equally active, but this does not support the 10% claim | The claim's persistence in popular culture despite scientific refutation indicates widespread acceptance despite evidence

google (gemini-2.5-flash-lite) · contradicted · 100%

The claim that humans only use 10% of their brain capacity is a persistent myth. Neuroscientific evidence indicates that humans utilize virtually all of their brain, with different areas being more or less active depending on the task, but no large portions of the brain remaining unused.

Key points: Neuroimaging studies (like fMRI and PET scans) show widespread brain activity even during simple tasks. | Brain damage to even small areas can result in significant functional deficits, indicating that most of the brain has a purpose. | Evolutionary pressures would likely not favor the development of such a large, unused organ. | The myth may have originated from misinterpretations of early 20th-century research or self-help motivational theories.

Limitations: While the myth is debunked, the precise 'capacity' of the brain is difficult to quantify definitively. | The concept of 'capacity' itself is broad and can be interpreted in various ways, though the 10% figure is demonstrably false in terms of brain activation.