The brain child needs a huge amount of energii
In adulthood, the male chimpanzee and the human male body weight is the same. But growing older and they are completely different. The man in the first year of life weighs twice as much as a chimpanzee, but eight chimpanzees had twice as heavy as a man. And in the 12 years the chimpanzee weighs as much as the adult, the person before six more years. The male gorilla, too, grows faster, the weight of an adult of 150 kg in five years, he weighs 50 kg, and ten - for 120 kg.
The brain of the human child needs energy. Since about four years before puberty brain absorbs glucose. During this period, the cerebral cortex uses almost twice as much glucose than before and after him. That's the problem: the body of a child less than one third of the body of an adult, but the size of the brain in this case is almost the same. Brain needs half the energy produced baby.
The greatest need for glucose brain feels when body growth slows. It is assumed that due to this slower muscle and brain receive the required amount of glucose. A blood child is always limited: about 3, 4 grams. Fortunately, the liver of the child can quickly produce glucose, and other organs to the brain for it is not "compete».
Other organs are energy sources that do not need the brain - eg fatty acids. Glucose is needed only skeletal muscle tissue during intense and prolonged stress. In adults, the liver quickly generates the right amount of glucose, so it is usually enough, and the muscles and brain. But under heavy braking may not be enough: it is dangerous even for adults, and for children especially. Fortunately, healthy children will calm down if muscles are working long and hard.
Big Brain - usually a smart brain. But it can be even smarter if the development formed stronger links (synapses). The more connections, the better cognitive performance. Synapses consume energy and, therefore, the brain child needs energy to grow. Slow growth of the child due to the fact that glucose is not enough for the growth of both the brain and skeletal muscle tissue.