Smart people should thank their mothers because, according to researchers, their mothers are mainly responsible for transmitting intelligence genes. Thus gender stereotypes that have survived for centuries are perhaps about to disappear. Single women who want an intelligent child don’t need to look for a Nobel Prize at the nearest sperm bank and it is likely that men will begin to see the intelligence of women as an important part of their attraction.
We know that intelligence has an hereditary component, but until a few years ago we thought that much of it depended on the father as well as on the mother. However, several studies revealed that children are more likely to inherit intelligence from the mother, because intelligence genes are located on chromosome X.
During the first experiment, researchers created embryos of rats that only had genes of the mother or of the father. But when it came time to transfer them to the uterus of an adult rat, the embryos died. So it was discovered that there are conditioned genes which are activated only when inherited from the mother and that are vital to the proper development of the embryo. On the other hand, the genetic heritage of the father is essential for the growth of the tissue that will form the placenta.
At that time, the researchers hypothesized that if these genes were important for the development of the embryo, it was also likely that they could play a major role in lives of animals and people, maybe they could even result in some brain functions. The problem was how to prove this idea, because embryos with genes from only one parent died quickly.