The important characters in children's cartoons are twice as likely to die as compared to those in the films meant only for adults, the study added.
"Rather than being innocuous and gentler alternatives to typical horror or drama films, children's animated films are, in fact, hotbeds of murder and mayhem," said one of the lead researchers James Kirkbride from University College London.
The researchers analysed the length of time it takes for key characters to die in the 45 top-grossing children's cartoons, released between 1937 ("Snow White") and 2013 ("Frozen"), and rated either as suitable for a general audience (G) or with parental guidance suggested (PG).
Violent content was compared with that from the two top-grossing films for adults released in the same year as each of the cartoons.
Film genres included 'horror' such as "The Exorcism of Emily Rose" and "What Lies Beneath", and thrillers, such as "Pulp Fiction", "The Departed", and "Black Swan".
Children's main cartoon characters were 2.5 times as likely to die as their counterparts in films for adults, and almost three times as likely to be murdered, the researchers found.
Parents of main characters were more than five times as likely to die in children's cartoons as they were in films targeted at adults.
Notable early screen deaths included Nemo's mother being eaten by a barracuda four minutes three seconds into "Finding Nemo"; Tarzan's parents being killed by a leopard four minutes eight seconds into "Tarzan"; and the character Cecil Gaines' father being shot in front of him six minutes into "The Butler".
The study appeared in the British Medical Journal (BMJ).
