阅读理解
What makes humans smarter than other animals? We've got a bigger brain, of course. But when it comes to brains, is bigger always better?
Traditionally, scientists have thought that humans' better intelligence (智慧) came mostly from the fact that our brains are three times bigger than those of our nearest living relatives, chimpanzees. People even used to believe that men are smarter than women because men have a little larger brains.
This, however, is not the truth. Scientists at University College London in the UK have found that brain organization, and not brain size, is the key to the advantage of human intelligence, reported Live Science.
Through millions of years of gradual development, our ancestors (祖先) were pushed to get smarter all the time so that they could meet the needs of new environments. However, holding this growing intelligence in increasingly large brains was not the best choice because bigger brains require more energy to power. "This is when reorganization may come into play," said Christophe Soligo, a member of the London research team.
In the study, scientists looked at the brains of 17 kinds of primates (灵长目动物) , including monkeys, apes and humans. They found that in the process of gradual development, brains didn't keep growing as a whole. Certain parts of the brain grew more than others as needed, and in this way they could make the best use of their limited brain space.
For example, when early humans were trying hard to live, the brain region (区域) which is in charge of using tools and finding food grew in size more than other regions. But in modern times, the prefrontal cortex (前额皮质) — the region in charge of social cognition (认知), moral judgments and goal-directed planning — grew more than the rest of the brain.
Think of the brain as a room. If a big room is poorly organized, it doesn't necessarily store more things than a smaller one.
Paul Manger, a professor, explains this using the example of whales. He told Scientific American: "Whales have big brains. But if you look at the actual structure (结构) of the brain, it's very simple. Brain size only matters if the rest of the brain is organized properly. "
