Evidence of the effects of family structure on high school completion is somewhat mixed; however, most research has demonstrated that adolescents growing up with both biological parents are more likely to graduate from high school than those who do not. Mensch and Kandel (1988) found that not growing up in a two-parent, biological family increased the likelihood of dropping out of high school. Similarly, McNeal (1995) found that living in a single-headed household is associated with an increased likelihood of dropping out, after controlling for prior achievement, academic track, SES, age, gender and race. Leventhal, Graber, and Brooks-Gunn (2001), in an analysis of a sample of Black urban children, also found that number of years the father was present was associated with increased likelihood to graduate from high school. In an analysis of a PSID data, McLanahan (1985) found that White adolescents who had recently experienced a parental marital separation were less likely to be in school at age 17 than adolescents who lived with both of their biological parents. Among Blacks, she found that adolescents who had recently experienced a parental marital separation, a parental divorce, or a paternal death were less likely to be in high school at age 17 than adolescents living with two biological parents. White and Black adolescents living in families headed by never-married mothers and those living with both parents did not differ significantly. Decreased income and increases in family stress account for much of the negative educational attainment effects of growing up without two biological parents among Whites (McLanahan, 1985).