So groups that provably have:
Higher rates of:
Depression
Suicide
Substance Abuse
Incarceration
Domestic Violence
Venereal Disease
Criminality
And lower life expectancy are better parents? Check.
They just redefine what outcomes are "bad" or ignore others.
For instance, the sodomite studies don't see the outcome of provably higher incidences of homosexual identity in same-sex raised kids as a negative.