People are told lies about homosexuality, ecologists anthropomorphize animal models like apes which don't even pair-bond.
The last stage of human development is socio-sexual. Reproductive exposure, early life, as well as neglect, abuse or trauma can cause misfiring of the normal reproductive psychosocial instinct. It can be conditioned, in the same way "fetishes" are conditioned. The psychological designation was removed because it was asserted that it did not cause dysfunction, even though it is precisely a dysfunction of the animal organism that characterizes it.
Biomedical pathologists have instilled an idea which is called the orientation model of human sexuality. Unfortunately, like Freud it is based on nothing and has no bearing on human behavior. The concept of a lifelong, exclusive, intrinsic attraction to the same sex is a recent invention. Up until this period, it has been understood in various modes all the way through antiquity: a vice, a rite of passage, a substitute, occasionally a sin -- but never an intrinsic mode of being, a "lifestyle", in the way one is hard-wired to feel warm near a fire.
It is made disgusting by evolution.
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