" Such decisions are made by the courts based on personal values, not empirical data. In 1999, the American Psychologist published one of the first research studies on the topic of adoptive parenting. "Deconstructing the Essential Father" (Silverstein & Auerbach, 1999) concluded that successful parenting is not gender specific and children do not need fathers or mothers. Rather, any gender configuration of adults could parent equally well. The implication that fathers were not necessary was extremely controversial.

Since then, numerous studies, such as one conducted last year by Ryan of the University of Texas School of Social Work, and Averett and Nalavany of East Carolina University (2009), show that there is no difference in emotional problems experienced by the children who are adopted by heterosexual and gay or lesbian parents. In order to determine their findings, the study's authors used survey results from parents who adopted children through Florida's public child welfare system as well as data from gay and lesbian couples throughout the country. It included 155 gay and lesbian couples and 1,229 heterosexual couples who answered questions about parent and child characteristics, family composition and dynamics, the child's pre-adoptive history of parents matters, . including maltreatment, and current emotional and behavioral functioning.

Just recently (2010), New York University researchers Biblarz and Stacey undertook a thorough review of relevant research to have a better understanding of research to date on how the gender of parents influence the children's upbringing. They found that research to date, does not support the claim that children need both a mother and a father and most of the enduring parental skills are most likely not dependent on gender. Rather, research has not indicated that compared to all other possible family configurations, those that are headed by married, biological parents are best for children. Further, studies thus far have not identified any parenting abilities that are exclusive only to one gender. These authors further confirm the growing consensus by noteworthy researchers concerning regarding fathering and child development in fact, based only on studies to date, it could be argued that two women are better parents on average than a woman pairing with a man, or at least than a woman and man with...

This is due partly to selection effects and also to women on average putting more into parenting investment and skills. Family structure alters these parental differences. Married heterosexual fathers normally score lowest on parental involvement and skills and often improve considerably when challenged with single or primary parenthood. If parenting without women encourages fathers to act more like mothers, the reverse appears to be partly accurate as well. Women who assume the role of parent on their own seem to acquire some traditional paternal practices and reap emotional benefits and costs. Also, single-sex parenting appears to enhance more androgynous parenting practices in women and men alike. The authors conclude that "no research supports the widely held conviction that the gender of parents matters for child well-being. To ascertain whether any particular form of family is ideal would demand sorting a formidable array of often inextricable family and social variables. We predict that even 'ideal' research designs will find instead that ideal parenting comes in many different genres and genders" (p.22)