What sort of rearing environment has the best effect on the child development? This is perhaps one of the most important questions concerning the well-being of children. Every year, surveys and research are conducted around the world to explore the question of what makes a better environment.

The rearing environment is a term that involves an extremely large number of factors. To see the influence of each factor on child development, the method of cohort research, which follows a large number of children over a long period of time, is generally used.

Cohort research assesses the effect that various environmental factors have on child development according to different measures of development (intelligent tests, language development tests, etc.), but when doing so, it is important not to forget the factors that are attributes of each of the children and their parents (so-called "confounding factors"). These include, for example, gender, premature birth or not (gestational age), birth order, types of illnesses contracted in the past (medical history), the presence of disabilities, etc. Furthermore, because parents are fundamental to a child's environment, such confounding factors such as educational level of the parents, employment status, annual income, marital status (unmarried, married, separated, divorced, separation by death), etc., are researched and included when undertaking a statistical analysis of the influence of the environment on child development.

I read many articles on cohort research conducted internationally, and have recently noticed that cohort research in the United States, in particular, has come to include some unfamiliar confounding factors. Among the factors involving parents, the attribute "incarcerated" now frequently appears. I first came across it in the article that I introduced in a previous blog on how stress can modify genes, which included "incarcerated" along with "divorced," "separation by death" as the attributes of the father.

In the research, "incarcerated" referred to a parent in prison for having committed a crime. In the United States, there are some 2.2 million people who are incarcerated, and of course, many of them are the parents of children. As stated in my article, the incarceration of a parent is very stressful (an adverse circumstance) for the child.

Children with an incarcerated parent not only deal with adverse circumstances such as living in poverty, but also experience psychological trauma as they are subject to the icy stares and the treatment of others who see them as the "child of a criminal." They are sometimes falsely viewed as having criminal tendencies themselves due to their family background, but research indicates that such behavior is rather due to psychological trauma stemming from poverty and treatment by society.

But, in Japan, what kind of life are children with an incarcerated parent leading? The prison population in Japan is somewhere between 70,000 and 80,000, a double-digit difference from that of the United States, but there are still many children with a parent in prison.

In the case of children who are orphaned by the death of a parent in traffic accident, financial assistance for education is available, but children with a parent in prison do not receive such assistance because of the prevailing view in line with the old saying that "the sins of the parents are visited upon the children." This is very worrisome. Like children who lose a parent in a traffic accident, these children cannot be held responsible.

Reference:
Mason DJ., Forced Separation of Children From Parents: Another Consideration. JAMA. 2018;320(10):963-964. doi:10.1001/jama.2018.12154