Illustration by Barry Falls

As New York State legislators wrestled with the question of same-sex marriage this week, I went back and reread the conversations on Motherlode over the past year about same-sex parenting.

Because any discussion of the first is really a discussion of the second.

And any discussion of the second finds that it is in the interest of the children to allow their parents to marry.

First point, same-sex parenting is becoming the “norm”:

The demographer Gary Gates of the Williams Institute at the University of California, Los Angeles, released his analysis of 2008 census data, which shows that 31 percent of same-sex couples who identify themselves as spouses are raising kids, compared with 43 percent of heterosexual couples. This is a jump even from the 2000 census, which showed that 1 in 5 male couples and 1 in 3 female couples were raising children, and a huge leap from 1990, when 1 in 20 male couples and 1 in 5 female couples had children under the age of 18.

And how are the children of these couples doing? Just fine, thank you. (Some might argue they are faring better, by certain measures, than children of heterosexual couples.) This from June of last year:

… a report released online today by the journal Pediatrics quantifies the dynamics of lesbian families, with either single mothers or same-sex couples. The study, “US National Longitudinal Lesbian Family Study: Psychological Adjustment of 17-Year-Old Adolescents,” is the latest from Dr. Nanette Gartrell, a psychiatrist who teaches at the UCLA School of Law and who has been tracking 186 lesbian mothers through a longitudinal study since 1986. There are now 78 adolescents in that group who have reached the age of 17. The only way to measure the effects of a nontraditional upbringing is to wait until a large enough cohort gets old enough, so only in the past few years has there been data on whether children raised by same-sex parents were measurably different from those raised by heterosexual parents. The answer is that these kids continue to do just fine. Better, in fact, although Dr. Gartrell is hesitant to trumpet that adjective. Consistent with the other research that is emerging as this population reaches critical mass, these children were found to fare better in measures of academic, social and psychological competence than a comparable group raised in more traditional homes. They were less likely to be rule-breakers or to exhibit aggressive behavior, though those who had felt “stigmatized” by outsiders because of their family structure were somewhat more likely to have behavior problems. The reason, Dr. Gartrell and her co-authors theorize, is that families raised by lesbian mothers are more likely to be deliberately planned. These mothers are more likely to have the resources to raise them and the time to devote to them.

And here’s a similar conclusion from a year earlier:

“These children do just fine,” says Abbie E. Goldberg, an assistant professor in the department of psychology at Clark University, who concedes there are some who will continue to believe that gay parents are a danger to their children, in spite of a growing web of psychological and sociological evidence to the contrary. Her new book, “Lesbian and Gay Parents and Their Children,” is an analysis of more than 100 academic studies, most looking at groups of 30 to 150 subjects, and primarily on lesbian mothers, though of late there is a spike in research about gay fathers. In most ways, the accumulated research shows, children of same-sex parents are not markedly different from those of heterosexual parents. They show no increased incidence of psychiatric disorders, are just as popular at school and have just as many friends. While girls raised by lesbian mothers seem slightly more likely to have more sexual partners, and boys slightly more likely to have fewer, than those raised by heterosexual mothers, neither sex is more likely to suffer from gender confusion nor to identify themselves as gay. More enlightening than the similarities, however, are the differences, the most striking of which is that these children tend to be less conventional and more flexible when it comes to gender roles and assumptions than those raised in more traditional families. There are data that show, for instance, that daughters of lesbian mothers are more likely to aspire to professions that are traditionally considered male, like doctors or lawyers — 52 percent in one study said that was their goal, compared with 21 percent of daughters of heterosexual mothers, who are still more likely to say they want to be nurses or teachers when they grow up. (The same study found that 95 percent of boys from both types of families choose the more masculine jobs.) Girls raised by lesbians are also more likely to engage in “roughhousing” and to play with “male-gendered-type toys” than girls raised by straight mothers. And adult children of gay parents appear more likely than the average adult to work in the fields of social justice and to have more gay friends in their social mix.

Umm, did I mention that the data show these children do just fine?

The reason most often given by opponents of single-sex adoption is that children do best with a mother and a father. Over the past year, a parade of studies have all set out to test that assumption. What makes this latest one different was that, for the first time, research on the social development and psychological health of children was not based on the opinions of their parents alone but also of outside observers (teachers and caregivers). And, also for the first time, a control group of heterosexual families was used. The University of Virginia and George Washington University researchers studied preschoolers who were adopted at birth by 27 lesbian couples, 29 gay male couples and 50 heterosexual couples. (Yet another groundbreaking aspect to this study was the number of gay men who were included. To date, most of the research has been on lesbian mothers.) What did they find? That it’s the quality of the parenting that creates a psychologically healthy child, not the sexual orientation of the parents.

So debate away. But please don’t pretend that your opposition to same-sex marriage has anything to do with protecting the children.