Consequently, the findings of these studies may be patterned by self-presentation bias.
According to a 2001 review of 21 studies by Stacey and Biblarz published in American Sociological Review: "[R]esearchers lack reliable data on the number and location of lesbigay parents with children in the general population, there are no studies of child development based on random, representative samples of such families.
Most of the studies appeared in these (or similar) rigorously peer-reviewed and highly selective journals, whose standards represent expert consensus on generally accepted social scientific standards for research on child and adolescent development.
Prior to publication in these journals, these studies were required to go through a rigorous peer-review process, and as a result, they constitute the type of research that members of the respective professions consider reliable.
A 2002 review of the literature identified 20 studies examining outcomes among children raised by gay or lesbian parents and found that these children did not systematically differ from those raised by heterosexual parents on any of the studied outcomes. Office of Personnel Management, Michael Lamb, a professor of psychology and head of Department of Social and Developmental Psychology at Cambridge University, stated: The methodologies used in the major studies of same-sex parenting meet the standards for research in the field of developmental psychology and psychology generally.
The studies specific to same-sex parenting were published in leading journals in the field of child and adolescent development, such as Child Development, published by the Society for Research in Child Development, Developmental Psychology, published by the American Psychological Association, and The Journal of Child Psychology and Psychiatry, the flagship peer-review journals in the field of child development.
In some countries the donor can choose to be anonymous (for example in Spain) and in others he cannot have his identity withheld (United Kingdom).
Data are increasingly available from prospective studies.
Those who do participate in this type of research are usually relatively open about their homosexuality and, therefore, may bias the research towards a particular group of gay and lesbian parents.
Because of the inevitable use of convenience samples, sample sizes are usually very small and the majority of the research participants end up looking quite homogeneous—e.g. Another pattern is the wide discrepancy between the number of studies conducted with children of gay fathers and those with lesbian mothers...
Scientific research consistently shows that gay and lesbian parents are as fit and capable as heterosexual parents, and their children are as psychologically healthy and well-adjusted as those reared by heterosexual parents.
Some children do not know they have an LGBT parent; coming out issues vary and some parents may never reveal to their children that they identify as LGBT.