The scientific debate is not as settled as proponents of gay rights claim. The studies, while positive in their conclusions, have generally been based on very small samples, not more than a dozen families. Some experts claim that there is also a volunteer bias, with the subjects of these studies usually supportive of the gay rights agenda and therefore keen on reporting positive results. Lastly, the researchers themselves can be biased and willing to find evidence to back a political agenda1.  1 Parke, Mary. "Are Married Parents Really Better for Children?".Center for Law And Social Policy. May 2003. (accessed 2 August 2011).