Infectious diseases make a person more stupid
During the last research, the scientists determined that diseases influence negatively human intelligence.
The researchers from the University of New Mexico analyzed the IQ level of Americans and determined that diseases have a disastrous influence on mental powers. They say: this relation is based on that fact that a lot of energy is necessary for work of a human brain, especially child’s brain. If the fight against the infection draws it, the brain suffers immediately.
Earlier, they considered that the farther a human lives from Tropical Africa, the more intelligent he is, as the brain does not have to make big efforts to survive in the region, where a human began to develop as a species initially. However, the investigation of an intellectual level of the Americans made give up on this theory.
Thus, the states, where the lowest indices were fixed, also were distinct in increased frequency of diseases. This correlation was true for other states as well. If the IQ was determined only by genetics, then the index would not be so easy to change, that supports the proposed version.