Editor's note - With the talk in the media about the Family Research Council's "hate group" designation, it is important that the gay community makes the case as to how FRC distorts social science to create anti-gay propaganda. With that in mind, I am repeating a post from a year ago because it is still relevant. The information is still on the FRC webpage.
On its 
Defend DOMA web page, the Family Research Council has a link, 
Ten Arguments From Social Science Against Same Sex Marriage which supposedly speaks against gay marriage but contains a number of misdirections.
In the piece, Family Research Council is basing the argument against gay  marriage on the claim that "children need both a mother and a father."
FRC makes the claim that lesbians household "raising children without a father" is wrong because according to them:
Among other things, we know that fathers excel in reducing  antisocial behavior and delinquency in boys and sexual activity in  girls.
And gay households "raising children without a mother" is wrong because:
fathers exercise a unique social and biological influence on  their children. For instance, a recent study of father absence on girls  found that girls who grew up apart from their biological father were  much more likely to experience early puberty and a teen pregnancy than  girls who spent their entire childhood in an intact family.
However, very little (if any at all) of the literature/studies FRC cites  to make these conclusions have anything to do with same-sex households.  
When the organization does address the studies involving same-sex households, it throws out an insulting addendum:
A number of leading professional associations have asserted  that there are "no differences" between children raised by homosexuals  and those raised by heterosexuals. But the research in this area is  quite preliminary; most of the studies are done by advocates and most  suffer from serious methodological problems. Sociologist Steven Nock of  the University of Virginia, who is agnostic on the issue of same-sex  civil marriage, offered this review of the literature on gay parenting  as an expert witness for a Canadian court considering legalization of  same-sex civil marriage:
Through this analysis I draw my conclusions that 1) all of the articles I  reviewed contained at least one fatal flaw of design or execution; and  2) not a single one of those studies was conducted according to general  accepted standards of scientific research.
This is not exactly the kind of social scientific evidence you would want to launch a major family experiment.
There is a huge problem with FRC citing Nock's testimony. He gave it in 2001. Since that time, there have been 
numerous other 
studies , as well as 
personal stories  from children in same-sex households which back up the conclusion that  same-sex households are a perfectly fine place to raise children.
Also, Nock's testimony was rejected by other researchers. 
(*see below) 
But keep in mind the phrase by FRC when criticizing studies involving same-sex households -  
most of the studies are done by advocates and most suffer from serious methodological problems.
If these studies is biased and have no credibility, then why do FRC have  no problem citing them when attacking same-sex households:
Judith Stacey-- a sociologist and an advocate for same-sex  civil marriage--reviewed the literature on child outcomes and found the  following: "lesbian parenting may free daughters and sons from a broad  but uneven range of traditional gender prescriptions." Her conclusion  here is based on studies that show that sons of lesbians are less  masculine and that daughters of lesbians are more masculine.
She also found that a "significantly greater proportion of young adult  children raised by lesbian mothers than those raised by heterosexual  mothers ... reported having a homoerotic relationship." Stacey also  observes that children of lesbians are more likely to report homoerotic  attractions.
Her review must be viewed judiciously, given the methodological flaws  detailed by Professor Nock in the literature as a whole. Nevertheless,  theses studies give some credence to conservative concerns about the  effects of homosexual parenting.
FRC's audacity is incredible here. The organization is saying "Stacey is  biased for same-sex marriage, so we cannot totally believe what she  says. However, we will believe the part which puts gay marriage in a  negative light."
The gymnastics behind this logic is astounding, especially when one  takes into account that this is a distortion of Stacey's study. She has  gone 
on record on more than one occasion complaining about how organizations like FRC cherry-pick her work. 
 
And on that same note, FRC also cited the work of Yale Child Study  Center psychiatrist Kyle Pruett to make the case against gay marriage in  the piece, even though Pruett has also 
complained  about how his work was being "cherry picked"  by religious right groups and spokespeople.
FRC is equally dishonest when it makes the claim that gay men will not be faithful in marriages.
One recent study of civil unions and marriages in Vermont  suggests this is a very real concern. More than 79 percent of  heterosexual married men and women, along with lesbians in civil unions,  reported that they strongly valued sexual fidelity. Only about 50  percent of gay men in civil unions valued sexual fidelity.
According to its footnotes, FRC received this information from two sources. One was:
Esther Rothblum and Sondra Solomon, Civil Unions in the  State of Vermont: A Report on the First Year. University of Vermont  Department of Psychology, 2003.
Of course this leads one to ask if this study looked at civil unions in  Vermont during the first year, then are the more recent updates.
The second source is more intriguing:
David McWhirter and Andrew Mattison, The Male Couple (Prentice Hall, 1984) 252.
Gay marriage wasn't legal in 1984.
The spin from the Family Research Council and those who support them, as   they trot out this mess, is that they are defending Christian beliefs  and morality.
That's an incorrect spin.
The Family Research Council is using lies and distortions to defend what they 
call Christian   beliefs. And I make that distinction because true Christian beliefs  don't  need to be defended through the spreading of propaganda and the  distortion of legitimate science.
Jesus said that "I am the way, the truth, and the light." He did  not  say "feel free to lie with impunity as long as you are doing it in   defense of my kingdom."
When FRC and other so-called pro-family groups engage in these  tactics,  they hurt the integrity of Christianity. They are sending a message  that underneath it all,  Christianity is a lie.
They send the message that Christian is fiction, because it if it were  real, those  who practice it wouldn't need to play such games as  manipulating science  or scaring heterosexuals into thinking that lgbts  are seeking to take away their children.
Organizations like FRC probably have the lgbt community beat on so many  levels such as planning, organization, and monetary resources.
But when it come to truth, when it come to basic honesty, the Family  Research Council and all of the other groups who wrap themselves up in  the flag of morality are sorely lacking.
And 
those are the value which they should consider central to  their message. But they don't. Instead, they reduce Christianity from a  religion of hope and love to a cynical way of gaining political power.
Bottom line - the way things are going, Jesus may have to come back, die  on the cross, raise Himself from the dead an immeasurable amount times  to stem the damage that FRC and other like-minded groups do in His name.
*There is a huge irony in the fact that FRC used both Steven Nock's  2001 testimony and Judith Stacey's work to demonize same-sex families  because Stacey published a scathing affadavit  which criticized Nock's testimony. In part it reads:
Professor Nock is a survey researcher and demographer,  which represents a specific methodology and a sub-field of inquiry  within sociological research. When Professor Nock provides his lengthy  description of research methodology, he adopts the extreme, untenable  position that the genre of large-scale survey research that he generally  conducts is the only acceptable research method in all of the social  science disciplines and subfields. 
 
 Professor Nock inappropriately applies this model of research, which  is only one model within his own particular sub-field of sociology –  demography – to an entirely different discipline, child development,  which is a branch of developmental psychology. This is a research  specialty and sub-discipline in which Professor Nock has no expertise.  The body of research with which he takes issue in his affidavit was  conducted primarily, if not exclusively, by psychologists with expertise  in the field of child development. None of the studies that Professor  Nock is evaluating were conducted by sociologists or by demographers.