In "Seduction of the Innocent", Wertham wrote about clear or hidden violence, sex, drug use, and other adult topics in "crime comics". Wertham used the words "crime comics" to mean popular comics about criminals and murder that were popular at that time. But, he also included superhero and horror comics in the same group of comics. He said that reading violent comics made children violent. However, this idea was from stories he had heard, not careful research.