When the films of Walt Disney Studios ushered in the era of popular American animation in the 1930s, animated films were strictly aimed at young audiences. Even when the films had a broad appeal and could be enjoyed by adults as well as children, the subject matter and storylines were always intended to be appropriate for children. The same was true of animation on television through most of the twentieth century; animated shorts and half-hour series on TV were geared toward children and, for the most part, excluded adults.
That changed in the 1960s, when The Flintstones debuted. This half-hour animated series was structured like a live-action situation comedy, and it borrowed heavily from popular live-action series like The Honeymooners. Although the show was still appropriate for young viewers, the humor and satire were often pitched at a level that could be fully appreciated only by adults.
The current trend in adult-oriented animation began in earnest in the 1990s, when The Simpsons became one of the most popular shows on TV. Like The Flintstones, it was heavily influenced by situation comedies, but The Simpsons reversed the focus of The Flintstones; in The Simpsons, the satire was sharp and sophisticated, and although children might have been able to appreciate it, the program was clearly intended primarily for adults.
Since The Simpsons, adult-oriented animated series often characterized by crude humor and adult themes have become nearly as widespread on TV as kid focused animation. Many of them are not only entertaining for adults, they are entirely unsuitable for children, a complete turn-around from the origins of animation.
In addition to the adult animation on American television, animated films from other cultures are often created with adults or at least mature young people in mind. Japanese anime, with its frequent violence and sexual situations, is a genre that seeks an older audience.