Final answer:
The belief that humans only use 10% of their brain is a myth, and it is false that this idea came from William James. Neuroscientific research demonstrates that all parts of the brain have some function over the course of a day, contradicting the 10% usage claim.
Step-by-step explanation:
False. The claim that humans only use 10% of their brains is a myth and does not originate from William James. The idea that people only use a fraction of their brain's potential is a popular misconception, often cited in literature and media. However, this notion is false and there is no substantial evidence to support the idea that 90% of the brain is inactive at any given time. Neuroscientific research has shown that even though not all areas are active simultaneously, over the course of a day, nearly every part of the brain is engaged in some activity.
While the exact origin of this myth is unclear, it is not accurately attributed to the psychologist William James, who was an advocate for the idea that people could further develop their mental capabilities. Rather, the myth seems to be a misinterpretation or exaggeration of some suggestive motivational speeches and literature on the potential of human development.