No Difference Thesis: A Household Built On Sand

Frank J. Moncher
December 03, 2013
Reproduced with Permission
Culture of Life Foundation

A study recently published in The Review of Economics of the Household entitled "High school Graduation Rates Among Children of Same-sex Households" found that the high school graduation rate for children living with gay and lesbian parents was only 65% of the graduation rate of children living in traditional heterosexual-parenting families. The researcher, Douglas W. Allen, Professor of Economics at Simon Fraser University in British Columbia, sampled 2006 Canadian census data to reach his conclusions. Unique among studies of this type, the sample was large enough and sufficiently robust to reliably examine the relationship between children's high school graduation rates and the type of household in which they lived. His conclusion contradicts the so-called "no difference thesis" so strongly asserted by advocates for same-sex marriage who tout their own studies, which are much smaller in scope and more biased in sampling. That thesis argues that children raised in same-sex households fare no differently from those raised by a father and mother.

So what has changed?

The Quality and Validity of Research

In psychological and other social science research, a common challenge is finding a sufficient number of people - in this case gay and lesbian households raising children - to reach statistically-meaningful conclusions. The group of children raised by parents involved in same-sex relationships is often relatively small, but the pathways through which families form these constellations vary widely. Many studies cited in defense of the "no difference" thesis have smaller samples which impacts the reliability of the findings, and hence calls into question their validity.

An additional challenge involves ensuring that the sample, even if sufficiently sized, is sufficiently diverse to be representative of the group being evaluated. In this instance, that means locating not only gay and lesbian parents who are active in various advocacy organizations, or skewed to the upper income brackets, but locating as well gay and lesbian parents across all social and economic spectrums. Building a sample from among a limited group solicited from gay activist organizations, representing a disproportionate number of children raised by upper class women with resources to supplement their own parenting efforts, is not a scientifically-valid approach for generalizing outcomes overall for children in these homes.

Allen's research, like that published recently by Mark Regnerus (see my previous review), is based upon larger, more representative samples of persons and families. Thus, his findings are more reliable and statistically valid. When commenting on the earlier, more-limited studies, Dr. Allen noted: "Despite the limited scientific validity of these studies, they all end with sweeping policy recommendations. It really is not a scientific literature, but rather a political literature targeted at judges, lawyers, and politicians." The Allen study reveals that when the entire group is looked at as a whole, the picture of how the children's lives are impacted by same-sex parents changes considerably.

In addition to utilizing a large and representative sample, Allen also examines other factors such as marital status, whether the family was led by gay versus lesbian persons, and the match between the gender of the parents and that of the child. Only the last of these proved significant, with the finding that daughters of same-sex parents do considerably worse than sons raised in like households. He offered the speculation that there might be some unique aspects of parenting that men and women provide differently that might be particularly impactful upon the developmental educational needs of girls. He cites medical research which demonstrates that when a biological father is present in the home, daughters begin menstruation at an older age. Later menstruation is likely correlated with delayed sexual activity, which may lead to a better likelihood of completing high school. He also dismisses a common explanation of poor school performance in general that suggests that children of same-sex couples may be discriminated against at school, stating that this seems less likely given the differential findings between boys or girls, who presumably would be discriminated against at similar levels if that were happening.


Dr. Allen's research is specific support of the more general finding that intact heterosexual marriage provides the best developmental outcomes for children across a wide range of measured criteria, including academic success. For certain, there are other dynamics and arrangements in households that place increased stress on a child and may impact their school performance adversely, among the most obvious are chronic marital conflict, abuse or neglect, and untreated mental illness or addiction in one parent or the other. What is not definitively known (see also) is whether it is the increased presence of these dynamics among those who identify as gay or lesbian that provides a direct link with academic distress, or perhaps something less direct or more subtle, but no less important.

An Hypothesis

A child's fundamental foundation for learning is built upon his or her family's healthy functioning. Although efforts to redefine and expand societal understanding of what constitutes a family abound, the research supports what I suspect is intuitively known by the children who are raised in homes where there is something other than a mother and father who love each other and love and care for their children: that is, there is something different about my living with two dads or two moms, and regardless of how much I am told otherwise, there is something missing. I suspect that many children in these situations do not feel able to ask the questions that spontaneously arise, and so continue to live with some measure of uncertainty. And this uncertainty has certain consequences for their development.