No. We use virtually all of our brain.

The 10% claim has no scientific support. Evolution would be unlikely to maintain such an expensive organ if most of it were unused. Neuroscience studies using lesion mapping, electrical stimulation, and imaging show that different regions serve specific roles, and that over a day nearly all of the brain is used. The myth likely persisted through misquoted early psychology and self-help claims about untapped human potential.

• Brain imaging (fMRI, PET) shows activity across essentially all brain regions over the course of a day, including during sleep.
• Damage to almost any brain area, even small ones, causes some deficit in function.
• The brain is about 2% of body weight but uses roughly 20% of the body's energy, which would be wasteful if 90% were idle.
• No brain region has been found to be completely silent or functionless.
• Not all neurons fire at once, but that is normal and necessary; simultaneous firing of all neurons would resemble a seizure.

The 10% myth likely arose in the late 19th or early 20th century from misinterpretations of early neuroscience research and popular self-help literature. Modern neuroscience conclusively demonstrates that all regions of the healthy brain have identified functions. While not every neuron fires simultaneously—which would trigger a seizure rather than enhance capability—virtually the entire brain is engaged across routine daily tasks.

• Functional brain imaging techniques like fMRI and PET show activity across the entire brain.
• The brain consumes roughly 20% of the body's energy despite representing only 2% of body mass.
• Damage to even minute areas of the brain almost always causes specific functional or cognitive deficits.
• Unused brain tissue degrades over time through natural cellular processes, leaving no large dormant regions.

Neuroscience has settled this: imaging, lesion studies, and metabolic measurements all show that we use essentially every part of the brain. Different regions are more or less active at different times, but no evidence supports a vast unused reserve. The 10% figure is a widely repeated myth, not a scientific finding.

• Modern fMRI and PET imaging show activity throughout the brain, not just in 10% of it.
• Even during sleep, brain regions remain metabolically active; no large 'silent' areas exist.
• Damage to almost any brain region produces specific impairments, which would not happen if 90% were unused.
• The brain consumes about 20% of the body's oxygen and energy despite being ~2% of body weight, inconsistent with 90% being idle.
• The myth's origin is unclear but has been traced to misquotes of early psychologists like William James and to marketing or self-help claims.

The idea that humans only use 10% of their brains is a persistent myth with no basis in neuroscience. Brain imaging technologies, such as fMRI and PET scans, demonstrate that nearly all regions of the brain are active, even during rest or simple tasks. Damage to even small areas of the brain can result in profound cognitive, motor, or sensory deficits, underscoring the importance of every part. Evolutionary biology also refutes this myth, as the brain is metabolically expensive to maintain, and natural selection would not favor the development of large, unused brain regions. The myth likely originated from misinterpretations of early neuroscience research or self-help marketing.

• Functional MRI (fMRI) and PET scans show activity throughout the brain, even during simple tasks.
• Brain damage to even small areas can have significant effects, proving their importance.
• The 10% myth has been debunked by neuroscientists for decades.
• Evolutionary biology supports full brain use, as maintaining unused brain tissue would be energetically costly.
• Neuroscientists like Barry Beyerstein have written extensively against this myth.