Here's a breakdown:
* Human brain size: 1,350 cubic centimeters (cc) on average
* Gorilla brain size: 450 cc on average
* Chimpanzee brain size: 370 cc on average
* Orangutan brain size: 390 cc on average
While size isn't the only factor determining intelligence, humans have a much larger brain volume compared to apes. This allows for more complex cognitive abilities, including language, abstract thinking, and problem-solving.