Found this quote in some old notes; unfortunately couldn't find the source again. It demonstrates a very basic and inexcusable fallacy used to condemn many things:

“With regard to polygamy, medical research has shown that women involved tend to have higher incidence of mental illness, including depression, anxiety, phobias, and somatization disorder. Children of polygamous unions have a higher incidence of antisocial behaviors, drug abuse and alcoholism, as well as poorer academic outcomes. These studies targeted populations around the world, not just in Mormon communities. Given these facts, the US government should move swiftly to take legal action against the organizers of this movement.”

The only thing necessary to demonstrate the foolishness and immorality of it is to turn it on something they instead prefer to protect, like so:

“With regard to people of darker skin, medical research has shown that women involved tend to have higher incidence of mental illness, including depression, anxiety, phobias, and somatization disorder. Children in darker skinned families have a higher incidence of antisocial behaviors, drug abuse and alcoholism, as well as poorer academic outcomes. These studies targeted populations around the world, not just in ghetto communities. Given these facts, the US government should move swiftly to take legal action against people with darker skin.”