<P> A variety of viewpoints exist and the debate is complicated by different interpretations of available research . The Institute for the Study of Civil Society reports that children of single parents, after controlling for other variables like family income, are more likely to have problems . The ONS reports that those children are twice more like to suffer from mental illness . Researchers show that children with no fathers are three times more likely to be unhappy, and are also more likely to engage in anti-social behavior, abuse substance and engage in juvenile deliquency . </P> <P> It is encouraged that each parent respect the other, at least in the child's presence, and provide child support for the primary caregiver, when parents are not married or separated . The civil behavior among separated parents has a direct effect on how child copes with their situation; this is especially seen in younger children who do not yet understand their familial separation, requiring both parents to establish a limited friendship to support the upbringing of their child . </P> <P> In this section we will use data from U.S. Census bureau and the National Assessment of Educational Progress to evaluate how the increase in single - parent households may have affected children's educational achievements . The percentage of children living with single parents increased substantially in the United States during the second half of the 20th century . According to Child Trends, 2013 only 9% of children lived with single parents in the 1960s--a figure that increased to 28% in 2012 . The main cause of single parent families are high rates of divorce and non-marital childbearing . According to Blankenhorn 1995, Fagan 1999, Pearlstein 2011, Popenoe 2009 and Whitehead 1997 researches, single parent family is the primary cause of school failure and problems of delinquency, drug use, teenage pregnancies, poverty, and welfare dependency in American society . Using multilevel modeling, Pong 1997 and Pong 1998 high proportions of children from single parent families perform very poorly on math and reading achievement tests in schools . </P> <P> In the United States, 83% of single parents are mothers . Among this percentage of single mothers: 45% of single mothers are currently divorced or separated, 1.7% are widowed, 34% of single mothers never have been married . Although decades ago, having a child outside of marriage and / or being a single mother was not prominent . Census information from 1960 tells us that in that year, only nine percent of children lived in single parent families . Today four out of every ten children are born to an unwed mother . </P>

What is the percentage of single parents in america