How can two brothers with similar genetic heredity and similar familiar ambience be so different? and how is it that this happens more often than the opposite?

Although two children of the same family can have a surprising similar physicist, the brothers tend to be more more different than seem in his intellect and especially in his personality. A reason, of course, there can be the genetic differences, which lead to answering in a different way before a similar environment. A child with a high Intellectual Coefficient can feel more stimulated by a room full of books and jigsaw puzzle that one with a greatly lower IQ.

Surprisingly nevertheless, the same family circle seems to do that the brothers are more different: even so much like two children without any familiar relation!. Seemingly, the experiences that affect deeply the development are not those that are similar for all the children in a family but those that are different.

These not shared environmental effects are a result of the exclusive environment in which every child grows in a family. What factors influence this not shared environment?
One is the familiar composition; the differences between the experiences of the children and the girls or between those who are born first and those who are born later. Different is the way like the parents and the brothers treat every child. Certain events, like an illness or an accident, as well as the experiences out of the hearth (teachers, friends...) affect a son and not other. While the heredity is the person in charge of most of the similarity between brothers, not shared environment is responsible for most of the difference.

The relations I genotipo-half-close they can play an important role in not shared environment. The genetic differences of the children can do that the parents and the brothers react to them in unequal form and treat them as a different form; the genes can influence how the children perceive and answer to this treatment or what his result will be. The children also mold their own ambiences for the decisions that they take, what they do and with whom, and his genetic composition influences these decisions. In other words "the genes guide our experiences". A child who has inherited an artistic talent can spend big part of his time creating "masterpieces", while a brother with an athletic inclination spends more time playing the ball with other children. This way, not only the capacities of the children (painting or soccer) develop in a different way, but his social lives also will be different. These differences tend to be accentuated as the children grow and have more experiences out of the family.