Ma`rifat

Abstract Fertility below the replacement level (fertility of less than two children) is one of the serious challenges in determining the population of a country, which occupies the minds of psychologists and sociologists. The fertility rate below the replacement level and its continuation in Iran has resulted in the spread of single-child families, and this can create a population crisis for the country in the coming years. Using a descriptive-analytical method, this paper seeks to investigate the causes of choosing one child by families and explain its consequences from different dimensions. The findings show that cultural factors, including idealism in raising children, individualism, consumerism, lifestyle and social factors, including women's employment, women's education and economic factors are effective in choosing to have only one child. Single child in three individual parts can lead to undesirable consequences, including filiarchy, dependence, loneliness; and family, including the weakening of family culture, ease of divorce and separation of parents, as well as social, including the reduction of kinship relationships and aging of the population. Therefore, in their population policies, it is necessary for the authorities to pay attention to the various reasons for choosing one child by families and to explain its various consequences to them.