Children are fully switch the attention of parents with relationships and sex on the process of education and care, according to researchers from Harvard University. Each mother known the night crying child, writes The Daily Mail. As a result, parents are tired, no time to sleep. This mechanism assistants called natural contraception.
After child birth and breast feeding continues for the period of absence of menstruation. Professor David Haig believes that natural mechanisms aimed at surviving their first child. Tired of the mother during nursing and care is one of the natural tactics developed during the process of evolution.
In addition, scientists have shown that the minimum intervals between pregnancies often lead to miscarriages. Particularly diseases and pathology of the fetus are found in poor nutrition and infections in the mother. Interesting and the fact that the child during adolescence starts to cry, just to attract attention.