A new study published in the February 2015 issue of the British Journal of Education, Society, and Behavioural Science appears to be the largest yet on the matter of same-sex households and children’s emotional outcomes. It analyzed 512 children of same-sex parents, drawn from a pool of over 207,000 respondents who participated in the (US) National Health Interview Survey (NHIS) at some point between 1997 and 2013.

Results reveal that, on eight out of twelve psychometric measures, the risk of clinical emotional problems, developmental problems, or use of mental health treatment services is nearly double among those with same-sex parents when contrasted with children of opposite-sex parents. The estimate of serious child emotional problems in children with same-sex parents is 17 percent, compared with 7 percent among opposite-sex parents, after adjusting for age, race, gender, and parent’s education and income. Rates of ADHD were higher as well—15.5 compared to 7.1 percent. The same is true for learning disabilities: 14.1 vs. 8 percent.

The study’s author, sociologist Paul Sullins, assessed a variety of different hypotheses about the differences, including comparative residential stability, experience of stigma or bullying, parental emotional problems (6.1 percent among same-sex parents vs. 3.4 percent among opposite-sex ones), and biological attachment. Each of these factors predictably aggravated children’s emotional health, but only the last of these—biological parentage—accounted for nearly all of the variation in emotional problems. While adopted children are at higher risk of emotional problems overall, being adopted did not account for the differences between children in same-sex and opposite-sex households. It’s also worth noting that while being bullied clearly aggravates emotional health, there was no difference in self-reported experience of having been bullied between the children of same-sex and opposite-sex parents.

Vocal critics, soon to emerge, will likely home in on the explanatory mechanism—the fact that two mothers or two fathers can’t possibly both enjoy a biological connection to a child—in suggesting the results of the study reveal nothing of value about same-sex households with children. On the contrary, the study reveals a great deal. Namely, there is no equivalent replacement for the enduring gift to a child that a married biological mother and father offer. It’s no guarantee of success. It’s not always possible. But the odds of emotional struggle at least double without it. Some critics might attribute the emotional health differences to the realities of “adoption by strangers,” but the vast majority of same-sex couples in the NHIS exhibited one parent with a biological relationship with the child.

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Even research on “planned” same-sex families—those created using assisted reproductive technology (ART)—reveals the significance of biological ties. Sullins notes such studies

have long recognized that the lack of conjoined biological ties creates unique difficulties and relational stresses. The birth and non-birth mother . . . are subject to competition, rivalry, and jealousy regarding conception and mothering roles that are never faced by conceiving opposite-sex couples, and which, for the children involved, can result in anxiety over their security and identity.

The population-based study pooled over 2,700 same-sex couples, defined as “those persons whose reported spouse or cohabiting partner was of the same sex as themselves.” This is a measure similar to that employed in the US Census, but it has the advantage of clarity about the sexual or romantic nature of the partnership (being sure to exclude those who are simply same-sex roommates). Among these, 582 had children under 18 in the household. A battery of questions was completed by 512 of them.

Lies, Damned Lies, and Statistics

This is not the first time the NHIS data have been used to analyze same-sex households and child health. A manuscript presented at the 2014 annual meeting of the Population Association of America assessed the same data. Curiously, that manuscript overlooked all emotional health outcomes. Instead, the authors inquired only into a solitary, parent-reported measure of their “perception of the child’s overall health,” a physical well-being proxy that varies only modestly across household types. Hence, the authors readily concluded “no differences.”

I’m not surprised.

This juxtaposition provides a window into the state of the social science of same-sex households with children. Null findings are preferred—and arguably sought—by most scholars and journal editors. Indeed, study results seem to vary by author, not by dataset. It is largely a different approach to the presentation of data that distinguishes those population-based studies hailed by many as proof of “no differences” from those studies denounced by the same people as “junk science.”

In fact, population-based surveys of same-sex households with children all tend to reveal the same thing, regardless of the data source. It’s a testimony to the virtues of random sampling and the vices of relying on nonrandom samples, which Sullins argues—in another published study—fosters “a strong bias resulting in false positive outcomes . . . in recruited samples of same-sex parents.” He’s right. Published research employing the New Family Structures Study (NFSS), the ECLS (Early Childhood Longitudinal Study), the US Census (ACS), the Canadian Census, and now the NHIS all reveal a comparable basic narrative, namely, that children who grow up with a married mother and father fare best at face value.

The real disagreement is seldom over what the data reveal. It’s how scholars present and interpret the data that differs profoundly. You can make the children of same-sex households appear to fare fine (if not better), on average, if you control for a series of documented factors more apt to plague same-sex relationships and households: relationship instability, residential instability, health and emotional challenges, greater economic struggle (among female couples), and—perhaps most significantly—the lack of two biological connections to the child. If you control for these, you will indeed find “no differences” left over. Doing this gives the impression that “the kids are fine” at a time when it is politically expedient to do so.

This analytic tendency reflects a common pattern in social science research to search for ‘‘independent’’ effects of variables, thereby overlooking—or perhaps ignoring—the pathways that explain how social phenomena actually operate in the real world. By way of a helpful comparison, I can state with confidence that after controlling for home ownership, residential instability, single parenthood, and neighborhood employment levels, there is no association between household poverty and child educational achievement. But it would be misleading to say this unless I made it clear that these were the pathways by which poverty hurts educational futures—because we know it does.

The academy so privileges arguments in favor of same-sex marriage and parenting that every view other than resounding support—including research conclusions—has been formally or informally scolded. I should know. The explosive reaction to my 2012 research about parental same-sex relationships and child outcomes demonstrates that far more is at work than seeking answers to empirical research questions. Such reactions call into question the purpose and relevance of social science. Indeed, at least one sociologist holds that social science is designed “to identify and understand the various underlying causal mechanisms that produce identifiable outcomes and events of interest.” That this has not been the case with the study of same-sex households raises a more basic question.

Is the point of social science to win political arguments? Or is its purpose to better understand social reality?

What to Expect from a Topic Emerging from Its Infancy

One byproduct of better data—or perhaps the smell of impending victory by proponents of civil same-sex marriage in America—may be greater intellectual honesty about such relationships. Indeed, researchers have admitted the tendency to downplay “any inequities between same-sex partners . . . in part because of the dominant mantra that same-sex couples are more equal than different sex couples.”

It’s not the only consequential admission. Scholars are increasingly—and openly—squabbling over the nature of sexual orientation itself, signaling the comparative infancy of the social science here. Moreover, there’s a good deal of sexual identity switching being reported among young adults, a fact that does not comport with a honed narrative of immutability.

So should scholars trust self-reported sexual orientations? If people report something different a few years later, should we attribute this to their malleable sexuality or consider them heterosexual “jokesters” bent on messing with survey administrators? It is profoundly ironic that social scientists make strong social constructionist arguments about nearly everything except sexual orientation.

Stanford demographer Michael Rosenfeld’s survey project How Couples Meet and Stay Together (HCMST) reveals that while only 3 percent of heterosexual married persons reported being “at least sometimes attracted” to persons of a gender other than the gender of their current partner in the past year, the same was true of 20 percent of men in same-sex relationships and 33 percent of women in same-sex relationships. While the malleability of self-identified lesbian women is now taken for granted among social scientists of sexuality, the one-in-five figure among men in gay relationships is higher than most would guess.

In keeping with the data, expect those robust legal arguments leaning on the immutability of sexual orientation to bleed out within the next five years. Indeed, sociologists have never been fans of such biological essentialism, but have kept their mouths shut out of a sense of political duty to a movement they helped birth. No more.

Social scientists will soon wrestle with, rather than overlook, the elevated levels of poverty among well-educated lesbian women in America (as seen in the ACS, NFSS, NHIS, and HCMST). Until now, scholars predictably elected to employ income as a control variable in their studies of child and adult life outcomes, enabling them to avoid confronting the reasons for the unprecedented negative association of education with income among the population of same-sex female couples. Here again, it’s not been about understanding but about winning political battles.

We will also learn much more about the relationship stability distinctions that are common in the data between gay and straight parents. Unpublished research exploring the stability rates of same-sex and opposite-sex couples using data from yet more population-based surveys finds that claims about the comparability of same-sex and heterosexual couple stability (again, after a series of controls) are actually limited to couples without children. For couples with children, the dissolution rate for same-sex couples is more than double that of heterosexual couples. What remains unknown yet is whether this difference is an artifact that will disappear with legal marriage rights. I doubt it, given that same-sex relationships are distinctive in other ways, too. But it’s an empirical question.

As it turns out, the NFSS was not unique. It was simply more transparent than most datasets and offered a clearer glimpse into the messy reality of many Americans’ household histories. It did the work social science was intended to do—to richly describe and illuminate—but in so doing invited unprecedented hostility.

On a Thursday morning in late June 2015, Americans will be treated to the Court’s decision about altering an institution as old as recorded human history. But one thing that day will not change is the portrait of same-sex households with children. After a series of population-based data-collection projects, we know what that looks like: a clear step down, on average, from households that unite children with their own mother and father.

Biology matters—as new research released this week confirms—and no amount of legislation, litigation, or cheerleading can alter that. Whether the high court will elect to legally sever the rights of children to the security and benefits of their mother’s and father’s home is anyone’s guess.