A consistently prickly strain in the long-running debate over gay marriage is the question of whether same-sex couples can raise children as effectively as opposite-sex couples. Gay rights advocates now have new ammunition in the debate. A 25-year study evaluating the children of lesbian couples has concluded that such children are actually less likely to have behavioral problems than the national norm, and "rated higher in social, academic and total competence." CNN's Madison Park reports on the methodology:

The study, published Monday in the journal Pediatrics, followed 78 lesbian couples who conceived through sperm donations and assessed their children's well-being through a series of questionnaires and interviews.

...Gartrell started the study in 1986. She recruited subjects through announcements in bookstores, lesbian events and newspapers throughout metro Boston, Massachusetts; San Francisco, California, and Washington.

The mothers were interviewed during pregnancy or the insemination process, and additionally when the children were 2, 5, 10 and 17 years old. Those children are now 18 to 23 years old.They were interviewed four times as they matured and also completed an online questionnaire at age 17, focusing on their psychological adjustment, peer and family relationships and academic progress.

To assess their well-being, Gartrell used the Child Behavior Checklist, a commonly used standard to measure children's behavioral and social problems, such as anxiety, depression, aggressive behavior and social competence. The answers were coded into a computer and then analyzed. This data was compared with data from children of nonlesbian families.

The study invites any number of possible interpretations. For example, the national average includes many single-parent families, while this study observed only two-parent lesbian families. Or maybe the surveyed lesbian parents, who were recruited from coastal metro areas, are relatively wealthy and more able to afford things like private tutoring. Or perhaps the surveyed households have fewer children, as is typical for same-sex couples, and thus devoted more resources to each child. Whatever the case, gay rights advocates are sure to use the study to argue that same-sex couples should be granted equal parenting rights.