Final answer:
Despite having a smaller brain than Neanderthals, modern humans are more intelligent due to the organization and structure of the brain, particularly the development of the cerebral cortex, which allows for high levels of intelligence and complex social interactions.
Step-by-step explanation:
The fact that modern humans have a smaller brain size compared to Neanderthals has led to questions about the relationship between brain size and intelligence. It was once thought that a bigger brain meant more intelligence. However, it is the organization and structure of the brain that matters more than its size. The Neanderthal brain, for instance, had a less developed frontal region but a more developed back area, suggesting a different specialization, possibly as an adaptation to their environment.
During a period of rapid climate change between 800,000 and 100,000 years ago, the brain size of human ancestors increased significantly from about 600 cm³ to about 1400 cm³, and culture and technology evolved alongside biological evolution. These developments, driven by the need to adapt to an unpredictable environment, allowed humans to become more intelligent and to dominate various habitats across the world.
In comparison with our closest evolutionary relative, the chimpanzee, humans have a significantly larger brain. This increase in brain size is associated with the cerebrum, which in primates is larger relative to the rest of the brain and allows for higher levels of intelligence and complex social interactions. Consequently, the cerebral cortex, the part that has increased in surface area due to more folding, plays a crucial role. This increase in the cortex's surface area is associated with intelligence and complex behaviors found in some mammals, including humans.