The study was met with considerable criticism from many academics and scholarly organizations. Most notably, only two children in the study had actually lived with homosexually partnered parents for their entire childhoods. Many of the non-heterosexual parents were in previous heterosexual marriages, and had then gone on to be in a same-sex relationship at some point. Regnerus removed the effects of divorce, infidelity, single parenthood from his heterosexual control group, but not from the gay parent group. Thus, negative outcomes could be attributed to family disruption and divorce, as opposed to homosexual parenting. More importantly, large studies of twins separated at birth and raised in different environments found that they grew up to be just as similar as those raised together, and large adoption studies found that adopted children correlated with their biological parents for genetic reasons, not their adoptive parents. Thus, parents tend to have limited environmental effects on their children's behavior, and negative outcomes very likely correlate with shared genes between parents and children. A 2015 reanalysis raised serious questions about the validity of the study, suggesting misclassification of families, inconsistency in answers suggesting mischief, and evidence many respondents did not live with their non-heterosexual parents. When these cases were excluded the differences largely vanished.
