This prosaic French comedy with a poetic title, made in 1987, is the first feature of Etienne Chatiliez, who was France’s leading director of TV commercials at the time. One of his best-known ads, for a French hamburger chain, declares, If you’re going to eat shit, then you might as well eat this shit. The same might be said, alas, about this rather heavy-handed satire about an upper-middle-class family and a poor family in a small town who discover that 12 years earlier two of their children (Valerie Lalande and Benoit Magimel) were switched shortly after birth by a nurse taking revenge on her lover (Daniel Gelin), the doctor who delivered both babies. An experimental documentary on a similar subject, Francoise Romand’s Mix-up, is one of the great films of the 80s; Chatiliez’s film is basically a glib sleaze item that suggests most of John Waters’s limitations while providing relatively little of his wit. Most of the laughs are provided by strident overdefinition of the lifestyles of the two families and the complications that ensue after the 12-year-olds are switched a second time. With Helene Vincent, Andre Wilms, Catherine Hiegel, Catherine Jacob, and Patrick Bouchitey. (JR)