Figure 3.

Combined parental age and education. Point estimate of odds ratio; bar indicates 95% confidence limits around point estimate; * p-value < 0.05; ** p-value < 0.005. FM UE, Father and mother uneducated; HS/UE, both parents high school, or one high school and the other uneducated; F CG: father has 4 or more years college and mother, high school or uneducated; M CG, mother has 4 or more years college and father, high school or uneducated; FM CG, both parents have 4 or more years of college.