The Research on Same-Sex Parenting: “No Differences” No More

Report Marriage and Family

The Research on Same-Sex Parenting: “No Differences” No More

April 23, 2015 5 min read Download Report
Jamie Hall
Jamie Hall
Research Fellow, Center for Data Analysis
Jamie was a Research Fellow for quantitative analysis in the Center for Data Analysis at The Heritage Foundation.

In its 2004 endorsement of what is commonly referred to as the “no differences” theory, the American Psychological Association (APA) declared that “there is no scientific evidence that parenting effectiveness is related to parental sexual orientation: lesbian and gay parents are as likely as heterosexual parents to provide supportive and healthy environments for their children,” and “research has shown that the adjustment, development, and psychological well-being of children is unrelated to parental sexual orientation and that the children of lesbian and gay parents are as likely as those of heterosexual parents to flourish.”[1]

These conclusions have been cited in numerous amicus briefs filed in court cases, including Obergefell v. Hodges,[2] the marriage case scheduled to be argued before the Supreme Court on April 28, 2015. In recent years, however, this position has been contradicted by more rigorous studies indicating that children raised by parents in a same-sex relationship face greater emotional, developmental, and other difficulties than those raised by mothers and fathers, particularly by their married biological parents.

Flawed Early Studies Found No Differences

It is well understood in experimental design that the preferred method is to conduct (1) a blind experiment (2) on a representative sample (3) using a statistically powerful hypothesis test. Early studies of parents in a same-sex relationship were lacking in at least one of these three design criteria, and most such studies were lacking in all of them.[3]

First, the participants were aware that the purpose was to investigate same-sex parenting and may have biased their responses in order to produce the desired result.

Second, participants were recruited through networks of friends or through advocacy organizations, resulting in a sample of same-sex parents of higher socioeconomic status than is typical of parents in a same-sex relationship generally.

Third, on average, samples of fewer than 40 children of parents in a same-sex relationship virtually guaranteed findings of no statistically significant differences between groups.

While many individual authors acknowledged the difficulties of studying a group that is relatively rare and difficult to identify through typical survey methods, the APA nonetheless used these flawed studies as a whole to support the “no differences” theory.

New Family Structures Study Indicates Differences Exist

In 2012, in his New Family Structures Study, Dr. Mark Regnerus, an associate professor of sociology at the University of Texas at Austin, addressed each of the three main problems with the earlier studies.[4] His research found that, similar to children from non-intact families, those children who at some point during their childhood lived with one parent and that parent’s same-sex partner fared, on average, significantly worse than children of married biological parents on a multitude of measures, including their educational progress as children and eventual employment and dependence on public assistance in adulthood.[5] His study admittedly could not determine the causes of these differences, but their mere presence seriously challenges the notion that the “no differences” conclusion is settled science and demonstrates the need for further research into these matters.[6]

Differences Recently Shown Using Government Health Survey Data

Dr. Donald Paul Sullins, a professor of sociology at the Catholic University of America, recently published a series of studies[7] that are among the most methodologically sound on the subject of same-sex parenting. He employs the National Health Interview Survey, a large, statistically representative survey containing various measures of physical and mental health, along with appropriate demographic control variables, that the Centers for Disease Control and Prevention has conducted since 1957. Using the most recent data, from 1997 to 2013, out of 207,007 children, he finds 512 (or 0.25 percent) whose parents were in same-sex married or cohabiting relationships at the time of the survey.

Controlling for child sex, age, and race and parents’ education and income, Dr. Sullins finds that children of parents in same-sex relationships fare significantly worse than those of opposite-sex parents on nine of 12 measures of emotional or developmental problems and their use of mental health treatment. In general, children of parents in same-sex relationships are about two to three times more likely to experience such problems.

In his most extensive statistical analysis, in which he also takes into account relationship stability, stigmatization, and parents’ psychological distress, Sullins finds the prevalence of emotional problems among children living with same-sex parents to be 4.5 times as high as among children living with their married biological parents, three times as high as children living with a married stepparent, 2.5 times as high as those with cohabiting parents, and three times as high as children with a single parent.

Further analyzing the data, he replaces the three variables mentioned in the previous paragraph with a single variable measuring biological parentage[8] and finds that:

Biological relationship, it appears, is both necessary and sufficient to explain the higher risk of emotional problems faced by children with same-sex parents…. The primary benefit of marriage for children, therefore, may not be that it tends to present them with improved parents (more stable, financially affluent, etc., although it does this), but that it presents them with their own parents…. Future research is needed to determine the mechanisms by which biological parentage affects child emotional wellbeing.[9]

The American College of Pediatricians et al., in their April 3, 2015, amicus brief in Obergefell v. Hodges, cite just-released work in which “Sullins found that, while outcomes for children with opposite-sex parents improved if their parents were married, outcomes for children with same-sex parents were notably worse if their parents were married rather than unmarried.”[10] In this latest study,[11] using data from the congressionally mandated National Longitudinal Survey of Adolescent to Adult Health (the primary data source for the three best studies used to support the “no differences” theory), Dr. Sullins finds that children of reported married same-sex parents are more likely than those of unmarried same-sex parents, unmarried opposite-sex parents, or married opposite-sex parents to experience depressive symptoms, unhappiness, daily fear or crying, and anxiety.

Furthermore, about a third of children raised by same-sex married parents report having been sexually abused by a parent or caregiver prior to 6th grade, a rate more than five times as high as children with any other category of parents, and among those who had ever had sex, about two-thirds of those raised by same-sex married parents report having been forced to do so against their will, a rate three to seven times as high as among those raised by any other category of parents. The magnitude of these differences is so great that, despite a small sample size, they are statistically significant, and further research is needed to determine their cause.

Research Does Not Support the Rush to Redefine Marriage

Decades of social scientific research shows that children, on average, fare best if raised by their own married biological parents. Relative to the intact family, other family forms tend to provide a less than optimal environment for children. This is not to say that every intact family is perfect or that every non-intact family is disadvantageous for children; rather, the data suggest that on average at the aggregate level, children are more likely to thrive when raised by their married biological mother and father.

New research findings raise significant concerns about how being raised by same-sex parents affects children and provide ample reason to slow the rush to redefine marriage. If, as the latest and most rigorous studies find, children living with same-sex married couples are at significantly higher risk for abuse or other negative outcomes, it is essential that political or judicial action take into account their best interests as well as those of their adult caregivers.

The Supreme Court should refrain from imposing a redefinition of marriage on the entire country. States should remain free to formulate marriage, divorce, adoption, and related policy as they seek to determine what best serves the needs of children in less than ideal circumstances without another state or the Supreme Court making these policy decisions for them.

—Jamie Bryan Hall is a Senior Policy Analyst in the Center for Data Analysis, of the Institute for Economic Freedom and Opportunity, at The Heritage Foundation.

[1] American Psychological Association, “Sexual Orientation, Parents, and Children,” July 28 and 30, 2004, (accessed April 21, 2015).

[2] Brief of the American Psychological Association, Kentucky Psychological Association, Ohio Psychological Association, American Psychiatric Association, American Academy of Pediatrics, American Association for Marriage and Family Therapy, Michigan Association for Marriage and Family Therapy, National Association of Social Workers, National Association of Social Workers Tennessee Chapter, National Association of Social Workers Michigan Chapter, National Association of Social Workers Kentucky Chapter, National Association of Social Workers Ohio Chapter, American Psychoanalytic Association, American Academy of Family Physicians, and American Medical Association as Amici Curiae in Support of Petitioners, Obergefell v. Hodges (6th Cir. 2015), (accessed April 21, 2015).

[3] Loren Marks, “Same-Sex Parenting and Children’s Outcomes: A Closer Examination of the American Psychological Association’s Brief on Lesbian and Gay Parenting,” Social Science Research, Vol. 41, No. 4 (July 2012), pp. 735–751, (accessed April 21, 2015).

[4] See New Family Structures Study, “About the Study,” Population Research Center, University of Texas at Austin, (accessed April 21, 2015).

[5] Mark Regnerus, “Parental Same-Sex Relationships, Family Instability, and Subsequent Life Outcomes for Adult Children: Answering Critics of the New Family Structures Study with Additional Analyses,” Social Science Research, Vol. 41, No. 6 (November 2012), pp. 1367–1377. In the follow-up study, Professor Regnerus specifically compared respondents who reported living with their mother and her female partner at some point during their childhood (85 cases in the data set) to children in intact families. Of those 85 cases, only 19 spent five consecutive years in that living arrangement, and only six experienced 10 consecutive years. This category of living with the parent and the parent’s same-sex partner does not include the few cases of children who lived with their father and his male partner. There are two additional comparison categories in which the respondents reported that their mothers had a same-sex relationship but did not live with the partner and where the father had a same-sex relationship.

[6] David J. Eggebeen, “What Can We Learn from Studies of Children Raised by Gay or Lesbian Parents?” Social Science Research, Vol. 41, No. 4 (July 2012), pp. 775–778.

[7] Donald Paul Sullins, “Emotional Problems Among Children with Same-Sex Parents: Difference by Definition,” British Journal of Education, Society and Behavioural Science, Vol. 7, No. 2 (January 25, 2015), pp. 99–120.

[8] That is, he categorizes children according to whether they live with none, one, or two of their biological parents, regardless of their parents’ gender, sexual orientation, or marital status.

[9] Sullins, “Emotional Problems Among Children with Same-Sex Parents.”

[10] Brief of Amici Curiae American College of Pediatricians, Family Watch International, Loren D. Marks, Mark D. Regnerus and Donald Paul Sullins in Support of Respondents, Obergefell v. Hodges (S. Ct. 2015), p. 35, (accessed April 21, 2015).

[11] Donald Paul Sullins, “The Unexpected Harm of Same-Sex Marriage: A Critical Appraisal, Replication and Re-Analysis of Wainright and Patterson’s Studies of Adolescents with Same-Sex Parents,” Catholic University of America, Marriage and Religion Research Institute, April 2, 2015.


Jamie Hall
Jamie Hall

Research Fellow, Center for Data Analysis