The movie puts forth for your viewing pleasure a carnival's worth of "freaks", men and women of dramtically different physical and in some cases mental shapes, sizes, and configurations. These are people who vary from the norm so drastically, that they make a stranger stop short, perhaps even gasp unavoidably. Some suffer in their existences, and some revel in their differences, but as we learn in this movie all are people with the full range of emotions and beliefs which inform and motivate all of us. While apart, we know they are still with us, that's the attraction and the repulsion. There, but for the grace of God go we.
The movie is a rough adaptation of a bleak 1923 short story by Tod Robbins. The story is titled "Spurs" and its not like the movie actually save for the fact that the story revolves around a small man who falls in love with a beautiful woman who mistreats him mightily and suffers for it. The themes remain intact, but the details are wildly and vividly different. If you've never read "Spurs" the story will not ruin the movie and if you've seen Freaks, you will not be disappointed I think in the story it sprang from.
I found the story in a collection edited by James Ellroy and Otto Penzler titled The Best American Noir of the Century. But if you like you can find the tale here.