Does child rearing by homosexual couples have any measurable negative effects?

Question

There is a widespread belief that there are adverse effects on children reared in same-sex-parents households compared to male+female household (I can add random googled cites if necessary, but the existence of laws preventing homosexuals to adopt should be enough evidence for that belief).

The effects could be either from absence of one of the sexes, OR from having "extra same sex parent".

Leaving aside non-scientific (though sometimes true) anecdotal responses that some M+F parents are worse for the child being reared than a well-motivated and caring M+M/F+F couple, my question is:

Is there any valid scientific study (preferably long term) that verifies the effects on the children of having two-male or two-female parent household (compared to 100% identical otherwise M+F household, and/or single-parent one). I'm looking for things such as, for example:

• Sexual behavior differences (e.g. early sexual activity, risky sexual behavior etc..). I would lump in "rates of homosexuality" into this - assuming Kinsey graduated scale (as opposed to simpleton gay/straight), it's possible that kids who are biologically Kinseyity-X% gay would be more likely to act on that than those from straight households.

• Rate of relationships/marriage for straight offspring of same gender (in other words, proof of common belief that having a father figure is essential for a daughter to be able to establish healthy relationships with males later in life)

• Socioeconomic success

• IQ

I'm thinking a good study to that effect would include control groups from both 2-straight-parents households, same-sex ones as well as single-parent.

What I'm looking for is whether there are any studies that, correcting for other sources of variation, exibit systemic differences (or lack thereof) in offspring that are similar between F+F household and single-mother one, e.g. stem from a lack of father (as opposed to having a second mother).

Or studies that are vice versa, showing that there are differences (or lack thereof) between same-sex-romantic-partner household reared children compared to same-sex-non-romantic-partners ones (e.g. a child reared by lesbian parents vs a mother and an aunt)

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P.S. As a background, a lot of people I know (myself included) have only ONE criteria for deciding whether to support things like gay marriage/gay adoption etc...: what does science say on the matter of "gay child rearing"

Answer 1

TL;DR Version:

There are some significant problems with the APA's claim in 2005 that there are no negative effects. Further research (with larger sample sizes, more representative participants, more outcomes analyzed, and longer-running) is necessary to determine if there are negative effects.

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There's a good paper titled "Same-Sex Parenting and Children’s Outcomes: A Closer Examination of the American Psychological Association’s Brief on Lesbian and Gay Parenting". They give a pretty good summary of what they are looking at:

       The overarching question of this paper is: Are the conclusions of the research presented in the 2005 APA Brief on “Lesbian and Gay Parenting” valid and precise, based on the cited scientific evidence? In the present paper, seven questions are posed, examined, and addressed:

  (1) How culturally, ethnically, and economically diverse were the gay/lesbian households in the published literature behind the APA Brief?

  (2) How many studies of gay/lesbian parents had no heterosexual comparison group?

  (3) When there were comparison groups, which groups were compared?

  (4) Does a scientifically-viable study exist to contradict the APA’s published statement that "not a single study has found children of lesbian or gay parents to be disadvantaged"?

  (5) What types of outcomes have been investigated?

  (6) What do we know about the long-term outcomes of children of lesbian and gay parents?

  (7) Have the studies in this area committed the type II error and prematurely concluded that heterosexual couples and gay and lesbian couples produce similar parental outcomes?

The 2005 APA Brief in question states that

Not a single study has found children of lesbian or gay parents to be disadvantaged in any significant respect relative to children of heterosexual parents.

In short, the paper points out multiple significant flaws in the research referenced by that brief. The paper does not question the validity of the research done, but it does show how we should be highly skeptical of the claim made by the APA until further research has been done.

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Regarding what the paper found for each of the seven questions:

In summary response to Question 1 ("How culturally, ethnically, and economically diverse were the gay/lesbian households in the published literature behind the APA Brief?"), the reader may ascertain that none of the cited articles (pp. 23–45) focus on African-American, Latino, or Asian-American families. Further, many studies do not include any minority individuals or families. Finally, comparison studies on children of gay fathers were almost non-existent as well. By their own reports, social researchers examining same-sex parenting have repeatedly selected non-representative, homogeneous samples of privileged lesbian mothers to represent all same-sex parents. This pattern across three decades of research raises significant questions regarding lack of diversity and lack of generalizability in the same-sex parenting studies.

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How many studies of gay/lesbian parents had no heterosexual comparison group? (This is actually the response for question two)

Of the 59 publications cited by the APA in the annotated bibliography section entitled ―Empirical Studies Specifically Related to Lesbian and Gay Parents and Their Children‖ (pp. 23–45), 33 involved a heterosexual comparison group. In direct response to Question 2, 26 (44.1 percent) of the studies on same-sex parenting did not include a heterosexual control group. In well-conducted science, it is important to have a clear comparison group before drawing conclusions regarding differences or the lack thereof. We see that nearly half of the ―Empirical Studies Specifically Related to Lesbian and Gay Parents and Their Children‖ referenced in the APA Brief allowed no basis for comparison between these two groups (see Table A). To proceed with precision, this fact does not negate the APA claim. It does, however, dilute it considerably as we are left with not 59, but 33, studies with heterosexual comparison groups.

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When there were comparison groups, which groups were compared?

Because children in marriage-based intact families have historically fared better than children in cohabiting, divorced, step, or single-parent families on the above outcomes, the question of what "groups" researchers selected to represent heterosexual parents in the same-sex parenting studies becomes critical.

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In total, in at least 13 of the 33 comparison studies listed in the APA Brief’s list of "Empirical Studies" (pp. 23–45) that include heterosexual comparison groups, the researchers explicitly sampled "single parents" as representatives for heterosexual parents. The repeated (and perhaps even modal) selection of single-parent families as a comparison heterosexual-parent group is noteworthy, given that a nonpartisan Child Trends (2002) review has stated that "children in single-parent families are more likely to have problems than are children who live in intact families headed by two biological parents."

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As we return to the APA’s section of 33 published "Empirical Studies" (pp. 23– 45) that directly involve heterosexual comparison groups, we see that the repeated, and perhaps modal, practice of same-sex parenting researchers has been to use single parents as heterosexual representatives. Nebulously defined "mothers" and "couples" are frequently used as heterosexual comparison groups, but only in rare cases are explicitly intact, marriage-based families used as the group representing heterosexual parents. This is important because the intact, marriage-based family is the family form consistently associated with best children’s outcomes in large-scale research.

In other words, it appears much of the research has found children raised by homosexual parents to be comparable in outcomes to children raised in conditions known to be sub-optimal.

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Question 4 asked: Does a scientifically viable study exist to contradict the APA’s published statement that "not a single study has found children of lesbian or gay parents to be disadvantaged"? The answer is yes. Sarantakos (1996) controlled for "education, occupation, and socio-economic status" and then, based on teacher reports, compared marriage-based families with homosexual families and found nine significant differences—with children from marriage-based families rating higher in eight areas. By objective standards, compared with the studies cited by the APA Brief, the Sarantakos study was:

a) The largest study to examine children’s outcomes,

b) One of the most comparative (only about five other studies used three comparison groups), and

c) Perhaps the most comprehensively triangulated study (five data sources) conducted on same-sex parenting.

Accordingly, this study deserves the attention of scientists interested in the question of homosexual and heterosexual parenting, rather than the dismissal it received from APA. As we conclude the examination of Question 4, let us review a portion of APA’s published negation of Sarantakos’ study:

[Children Australia, the journal where the article was published] cannot be
considered a source upon which one should rely for understanding the state of
scientific knowledge in this field, particularly when the results contradict
those that have been repeatedly replicated in studies published in better
known scientific journals.

Patterson and the APA dismissed the Sarantakos study, in part, because it contradicted the "no significant difference" findings that had been "repeatedly replicated in studies published in better known scientific journals." For other scientists, however, the salient point behind Sarantakos’ findings is that the novel comparison group of marriage-based families introduced significant differences in children’s outcomes (as opposed to the recurring "no difference" finding with single-mother and "couple" samples). Additional studies with intact, marriage-based families as the heterosexual comparison group are conspicuously rare in the APA Brief’s list of "Empirical Studies Specifically Related to Lesbian and Gay Parents and Their Children" (pp. 23–45).

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In response to the present article’s Question 5 (what types of outcomes have been investigated for children of gay/lesbian families?), it may be concluded: In the same-sex parenting research that undergirded the 2005 APA Brief, it appears that gender-related outcomes were the dominant research concern, to the neglect of other important outcomes. To be more precise, Table A lists several categories of information regarding 59 published empirical studies; one of these categories is the "outcome studied." More than 20 studies have examined gender-related outcomes, but there was a dearth of peer-reviewed journal articles from which to form science-based conclusions in myriad areas of societal concern including: intergenerational poverty, criminality, college education and/or labor force contribution, drug/alcohol abuse, suicide, sexual activity and early childbearing, and eventual divorce as adults.

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Did any peer-reviewed, same-sex parenting study cited by the 2005 APA Brief (pp. 23–45) track the societally significant long-term outcomes into adulthood? No.

Is it possible that "the major impact" of same-sex parenting might "not occur during childhood or adolescence...[and that it will rise] in adulthood as serious romantic relationships move center stage"? Is it possible that "when it comes time to choose a life mate and build a new family" that the effects of same-sex parenting will similarly "crescendo" as they did in Wallerstein’s study? It is possible.

From a scientific perspective, the unfortunate answer to the question regarding the long-term (i.e., adult) outcomes of lesbian and gay parenting is that we have no empirical basis for responding, because not a single peer-reviewed comparison study has followed same-sex parented children across time and into mid-adulthood.

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Have the studies in this area committed the Type II error?

Same-sex parenting studies have not employed large enough samples to overcome the possibility, or probability, of the Type II error, thereby "substantially increasing [the] likelihood" of failing to find differences. Further, significant critiques provided by social research methodology specialists Lerner and Nagai (2001) were not cited in the 2005 APA Brief. If the conclusion to be drawn is that there are no parenting differences between same-sex and heterosexual couples, such a conclusion cannot be drawn at the present time, given this problem with the Type II error, pervasive in the same-sex parenting literature. The APA Publication Manual urges researchers to "take seriously the statistical power considerations" and "routinely provide evidence" of adequate statistical power and effect sizes, however, a review of the 59 articles cited in the APA Brief (pp. 23-45), revealed that only a few complied. Further examination indicated that of the comparison studies, zero studies reached the "minimum requirement" of 393 to detect a small effect size. Indeed, only two comparison studies reached half of the minimum requirement.

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Also, here's their overall conclusion:

We now return to the overarching question of this paper: Are we witnessing the emergence of a new family form that (unlike cohabiting, divorced, or single-parent families) provides a context for children that is equivalent to the intact family? Even after an extensive reading of the same-sex parenting literature, the author cannot offer a high confidence, data-based "yes" or "no" response to this question. The data are insufficient to support a strong claim either way, and thus insufficient to produce a definitive binary statement. Such a statement would not be grounded in science. Representative, large- sample studies are needed—many of them, including high quality longitudinal studies (i.e., Table B). Although some same-sex opponents have made "egregious overstatements" and, conversely, some same-sex parenting researchers seem to have implicitly contended for an "exceptionally clear" verdict of "no difference" between same-sex and heterosexual parents since 1992, a closer examination leads to the conclusion that strong assertions, including those made by the APA, were not empirically warranted.

The scientific conclusions in this domain will be clearer as researchers: (a) move from small convenience samples to larger nationally representative samples, (b) increasingly examine critical societal and economic concerns that emerge during adolescence and adulthood, (c) include more diverse same-sex families (e.g., gay fathers, racial minorities, and those without middle-high socioeconomic status), (d) include intact, marriage-based heterosexual families as comparison groups, and (e) acknowledge and respond to experts’ methodological critiques in the effort to refine and add validity and rigor to findings. In connection with this latter point, it is particularly vital that statistical power no longer be ignored. Taking these steps will help lead the field towards more nuanced and scientifically informed responses to significant questions affecting families and children.

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Update:

Here are two studies that show negative effects. They attempt to use more random samples in order to avoid self-selection bias. Neither can conclusively say what is causing the negative effects - from the former:

Although the findings reported herein may be explicable in part by a variety of forces uniquely problematic for child development in lesbian and gay families—including a lack of social support for parents, stress exposure resulting from persistent stigma, and modest or absent legal security for their parental and romantic relationship statuses—the empirical claim that no notable differences exist must go. While it is certainly accurate to affirm that sexual orientation or parental sexual behavior need have nothing to do with the ability to be a good, effective parent, the data evaluated herein using population-based estimates drawn from a large, nationally-representative sample of young Americans suggest that it may affect the reality of family experiences among a significant number.

Answer 2

There were several researches showing that there isn't any real difference.

The researcher and colleagues looked at data from 15 studies evaluating possible stigma, teasing, social isolation, adjustment, sexual orientation, and strengths. The findings were presented here at the American Academy of Pediatrics National Conference and Exhibition.

"The vast consensus of the studies is that children of same-sex parents do as well as children whose parents are heterosexual in every way," Dr. Perrin said. "In some ways, children of same-sex parents actually may have advantages over other family structures."

Based on nine studies from 1981 to 1994 of 260 children, aged three to 11 years, reared by either heterosexual mothers or same sex-mothers after divorce, the researchers found there was no difference in intelligence of the children, type or prevalence of psychiatric disorders, self-esteem, well-being, peer relationships, or parental stress. "The children all had a similar emotional experiences with divorce," she said.

medscape.com

Parenting by same-sex families is just as good -- if not slightly advantageous -- for children when compared to heterosexual families, a Justice Department study has concluded.

The paper references about 100 studies on parenting and children’s development.

canada.com

I am aware of only one study that showed some differences. I've never read it myself, however, it is discussed here:

A study from Australia (Sarantakos, 1996) has been cited as demonstrating deficits among children raised by gay and lesbian parents in Australia compared to children raised by heterosexual couples. The anomalous results reported by this study--which contradict the accumulated body of research findings in this field--are attributable to idiosyncrasies in its sample and methodologies and are therefore not reliable. An expert reading of the Sarantakos article reveals that certain characteristics of its methodology and sample are highly likely to have skewed the results and rendered them an invalid indicator of the well-being of children raised by gay and lesbian parents in at least three respects:

1. The children raised by gay and lesbian parents experienced unusually high levels of extreme social ostracism and overt hostility from other children and parents, which probably accounted for the former's lower levels of interaction and social integration with peers (see pp. 25-26);
2. Nearly all indicators of the children's functioning were based on subjective reports by teachers, who, as noted repeatedly by the author, may have been biased (see pp. 24, 26, & 30); and
3. Most or all of the children being raised by gay and lesbian parents, but not the children being raised by heterosexual married parents, had experienced parental divorce, which is known to correlate with poor adjustment and academic performance.

Indeed, although the differences Sarantakos observed among the children are anomalous in the context of research on parents' sexual orientation, they are highly consistent with findings from studies of the effects of parental divorce on children (see, e.g., Amato, 2001, and Amato & Keith, 1991).

The very same source also explicitly states, that there is no scientific evidence of any deficits of homosexual parents compared to heterosexual ones; and that there isn't even any dispute about that among scientists. Which I believe does answer your question; as far as it can be answered:

Some nonscientific organizations have attempted to convince courts that there is an actual scientific dispute in this area by citing research performed by Paul Cameron as supporting the existence of deficits in gay and lesbian parents or their children compared to heterosexual parents or their children. In fact, there is no scientific evidence of such deficits. Cameron's research is methodologically suspect. His key findings in this area have not been replicated and are contradicted by the reputable published research. Unlike research that makes a contribution to science, his key findings and conclusions have rarely been cited by subsequent scientific studies published in peer-reviewed journals as informing their scientific inquiry. For a detailed critique of the research project on which Cameron has based many of his published papers, see Herek (1998).

apa.org

Answer 3

I find Rob Watts' answer to be comprehensive, but since more research has been conducted since then, I want to add the following:

Since 2005, the APA has maintained basically the same position that they held then, as seen for example in their 2014 amicus brief for Obergefell v. Hodges. Here, they identified many of the same problems with the Mark Regnerus study as have been identified in the other answers here. They also have similar criticisms for Doug Allen's study, which found lower graduation rates for children who lived in homes with parents in a same-sex relationship.

However, as pointed out by Rob Watts, the strength of same-sex parenting studies is highly dependent on the control group and the controlled variables (are stable, married heterosexual parents being compared with stable, married homosexual parents, for example). It was very hard to find large, representative groups of stable same-sex couples before same-sex marriage was legalized and normalized in the west. Additionally, the lack of normalization of homosexual parenting made it difficult to determine whether the lower stability rates of same-sex couples was due to negative stigma or if they were intrinsic to the nature of homosexual couples. As a result, the studies cited by the APA in their amicus brief supporting their position of "no differences" only compare stable same-sex couples to stable heterosexual couples, and the APA uses research on the prevalence and effects of stigma to suggest that this may be causing differences in stability rates rather than intrinsic factors.

Recently, however, one study over the period 1995-2012 from Sweden, where same sex marriage was legalized in 2009 (their figure 6), and one study over the period from 2000-2014 in the US before it was legalized, have both determined that lesbian couples have significantly higher divorce/separation rates than those of gay and heterosexual couples, who share similar rates.

Moreover, statistics provided by the government of the Netherlands, where same-sex marriage was legalized in 2001, from 2010 to 2020, showed the following:

Of the women who married another woman in 2010, 26 percent were divorced after almost ten years (on 1 January 2020). This is almost twice as much as for married male couples (14 percent). The divorce rate among heterosexual couples is comparable to that of gay male couples: 16 percent were divorced after ten years.

These recent results, especially those for the Netherlands, and especially since only lesbian and not gay couples have higher rates of separation, suggest that the higher lesbian divorce rate is intrinsic to the relationship itself, and not due to stigma or other external factors. It has recently been suggested that women tend to initiate divorce more often than men due to higher standards for mate preference. Furthermore, the fact that, due to biological reasons, it is much easier and more likely for lesbian couples to raise children (see figure 4 in the Sweden study), children of same-sex couples are significantly more likely to have their parents separate.

Since the APA was depending on studies that controlled for the divorce rate, but recent evidence suggests the divorce rate may be intrinsically higher among same-sex couples, this raises some doubt over the APA's "no difference" finding.

As a side note, since same-sex attraction appears to be practically innate, or at least very difficult to control, studies comparing the wellbeing of children from heterosexual mixed-orientation marriages to those from same-sex marriages would need to be conducted in order to more accurately determine the effects of same-sex marriage on society.

Answer 4

A new study did find that in 25 of 40 social and economic measures that children raised by a gay parent had worse outcomes than children raised by two biological parents. New Family Structures Study

Mark Regnerus of the University of Texas at Austin surveyed 3,000 people between the ages of 18-39. Of the 3,000, 175 people said their mother had a same-sex relationship while 73 said the same about their father.

Out of the people surveyed, more people raised under gay parents were arrested, have a lower level of household income and also said they were negatively impacted growing up than those under biological parents.