Do you know more intelligent human ancestor were also existed on earth 50000 to 10000 years ago in comparison to today humans!

It was previously thought that intelligent people tend to have larger brains based on an assumption that larger brains contain more neurons and, consequently, possess more computational power but despite their comparatively high number of neurons -- the brains of intelligent people demonstrated less neuronal activity during an IQ test than the brains of the less intelligent individuals.

Intelligent brains possess lean, yet efficient neuronal connections, and boast high mental performance at low neuronal activity.

https://www.sciencedaily.com/releases/2018/05/180517102236.htm

It’s basically, how the brain is built and the neural pathways, not just the size.