Typical thinking might suggest the larger the brain, the more effective it is... The bigger the brain, the better isn’t necessarily true... Interesting read! Link: https://www.msn.com/en-us/health/other/brain-size-could-have-a-major-impact-on-autism-severity/ar-BB1nJIl9
Brain size no longer indicates higher intelligence. Modern humans actually have smaller brains (10 - 13%) than our ancestors 100,000 years ago. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10517302/ https://www.science.org/doi/full/10.1126/sciadv.abe2101
The research exploring the neurobiology of intellectual giftedness suggests that high intelligence is more a matter of connectivity within the brain than brain size. The brains of gifted individuals have more intricate and extensive neural connections.