A new study reveals that stepchildren have about twice the rate of serious behavioral problems as children in traditional nuclear families. James Bray, of the Baylor College of Medicine, Houston, observed that some stepfamilies are better than others at heading off potential conflicts.

He identified three types of stepfamilies:

• Neotraditional families -- in which the couple are family oriented and manage the household as partners -- are the most successful at fostering healthy adjustment for youngsters.

• Matriarchal families -- in which mothers take full charge of the children and fathers avoid parenting -- worked second best, but problems arose if stepfathers later decided they wanted to parent or if mothers decided they wanted help after all.

• So-called romantic partnerships -- in which both mother and father expect instant love between stepfathers and children -- typically split up eventually or evolved into one of the two other types.

Seven years after the step-marriages started, tests found that 20 percent of the youngsters experienced behavioral or mental health problems -- versus 10 percent of children in nuclear families.

Children may foment tension with their stepfathers and embrace their biological fathers. Bray advises stepparents not to pretend the biological parent isn't part of the picture, and make it clear that it is fine for the child to love that parent.