Recently, re-reading RUMORS OF ANOTHER WORLD by Philip Yancey, I came across a story he shared from Annie Dillard. She tells of experiments conducted by entomologists’ (bug doctors) using butterflies.
The entomologists would take a male butterfly and place before him a painted cardboard imitation of a female butterfly. In repeated experiments, the male butterfly would, with great gusto, mount the cardboard replica. And he would not cease mounting it. In the meantime, a real-life female butterfly would be nearby, opening and closing her wings to gain the male’s attention. But he would not look.
I think pornography is doing something very similar to humans.