There is a principle that is a bar against all information; a proof against all arguments, and which cannot fail to keep a man in everlasting ignorance. That principle is contempt prior to investigation.
Herbert Spencer

I really do think we are going to find a biological standard that lends itself to homosexuality when mixed with the right parental mode and environment.

The more I read and contemplate this issue, personal to me and fraught with my prejudices and biases, I’m less and less inclined to see parental mode as being a significant factor or much of a factor, at all. Environment, we must remember, has to include the important prenatal environment in the womb. The time when the most critical development, divisional and organizational processes, gene/protein expression, hormonal triggering is occurring. All maintained by the mother’s own internal feeding of the developing child through her blood. The mother’s own stressors must of necessity be transmitted to the child throughout the time in the womb.
Mary, if you’re including prenatal development, in your term ‘environment’, I’d agree with you. If however, by environment you mean post-natal parenting or socialization factors, I won’t disagree entirely; but, frankly parenting modes/socialization are at the bottom of my hit-list of causative factors for homosexuality.

The overbearing, overprotective mother looms large in reparative therapy and appears to be an idea with a long history of tapping into collective fears and insecurities.

Interestingly, the protective maternal figure who comes to the rescue like Sigourney Weaver in that exoskeleton-machine from Aliens, in order to save her gay son from scary hetero bullies, also looms large in gay male “coming of age” fiction and movies.
(The early Russell Crowe film The Sum of Us was a refreshing exception to this cliche — in that movie, it’s the heterosexual father who is the gay son’s #1 Fan, defender, and booster, while the Ignorant Homophobe role goes to the prospective stepmother.)