Complex Brains as an Advertisement for Genetic Fitness

The healthy brain theory suggests that our brains are different from those of other apes not because extrava- gantly large brains helped us to survive or to raise offspring, but because such brains are simply better advertisements of how good our genes are. The more complicated the brain, the easier it is to mess up. The human brain's great complexity makes it vulnerable to impairment through mutations, and its great size makes it physiologically costly. By producing behaviors such as languag...

 Children Have an Innate Ability to Learn Language

The fact that all normal children acquire essentially comparable grammars of great complexity with remarkable rapidity suggests that human beings are somehow specially designed to do this, with data-handling or 'hypothesis-formulating' ability of unknown character and complexity.