So much for the Brady Bunch.
New research shows that children in blended families involving step- or half-siblings have more long-term behavioral problems in school and lower grades than other children.
Researchers at Florida State University studied data from more than 11,000 adolescents and their families found that the length of the step-family relationship had little effect on grades or behavior. Children did not appear to adjust or show improvements over time.
The results were especially pronounced for boys with step- or half-siblings. Their grades were on average one-quarter letter grade lower than boys living with only full siblings.
Interestingly, the best outcome occurred when both step- and half-siblings co-existed. Researchers believe such a situation may reflect an emphasis on child-rearing and stable relationships.
ABSTRACT: “Non-traditional” siblings and the academic outcomes of adolescents