of households include children, giving us an idea of how cohabitation could be considered a new normative type of family dynamic. As of 2012, 41% of all births in the US were to unmarried women. In three states (Mississippi – 55%, Louisiana – 53%, and New Mexico – 52%) births outside marriage were in the majority; the lowest percentage of births outside marriage was in Utah, at 19%. During the period 2006–2010, 58% of births outside marriage were to cohabiting parents. Contemporary objections to cohabitation Contemporary objections to cohabiting couples include religious opposition to non-marital unions, social pressure for couples to get married, and potential effects of cohabitation on a child's development. The rise in the number of cohabiting couples and children born out of wedlock in the Western world has made cohabitation a strong focus of sociological research. The rise in cohabiting couples in the United States, from around 450,000 in 1960 to 7.5 million in 2011 has been accompanied by US research performed on child development within cohabiting households. Opponents of cohabitation say non-marital parenting is an unsuitable environment for a child's development. One study from 2002 correlated lower numeracy skills and higher delinquency to children of cohabiting couples, however, recent studies that control for factors including poverty, the educational level of parents and violence in the home show children of cohabiting couples are developmentally similar to peers of comparable married couples. Effect on children In 2001, researchers compared teenage children living in a cohabiting household (a single mother and her boyfriend who was not related to the teenager) against peers in single-parent households. The results showed white and Hispanic teenagers had lower performance in school, greater risk of suspension or expulsion than peers from single-parent households, and the same rate of behavioral and emotional problems. A study on the 1995 and 2002 National Survey of Family Growth found increases in both the prevalence and duration of unmarried cohabitation. The study found that 40% of children in the United States would live in a cohabiting household by age 12, and children born to single mothers were more likely than those born to married mothers to live in a cohabiting household. The percentage of women ages 19–44 who had ever cohabited increased from 45% in 1995 to 54% in 2002. In 2002, 63% of women who graduate from high school were found to spend some time cohabiting, compared to