Nemo loses his mother to a barracuda in Finding Nemo (2003).

Children’s cartoons are more violent than films for adults, with their main characters more than twice as likely to be killed off as those in films for a more mature audience, according to research.

A study of cartoons released between 1937 and 2013 found they were “rife with death and destruction”, with content akin to the “rampant horrors” of popular films for adults.

Researchers Ian Colman and James Kirkbride, from the University of Ottawa in Canada and University College London, said: “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.”

Death and violence on screen can be particularly traumatic for young children, they said, and the impact can be intense and long-lasting. Because of this many parents will not let their children see the “endemic gore and carnage” typical of films aimed at adult audiences.

Children’s animated films are hotbeds of murder and mayhem

Their study, which is published in the Christmas issue of the British Medical Journal, assessed the amount of violence young children might be exposed to when watching films targeted at their age-group.

It examined the length of time it takes for key characters to die in the 45 top-grossing children’s cartoons, between Snow White and the Seven Dwarves in 1937 and 2013’s Frozen, films rated either as suitable for a general audience or with parental guidance suggested (PG). They also looked at whether the first on-screen death was a murder or involved a main character’s parent.

The study found that two-thirds of the cartoons depicted the death of an important character, compared with half of the adult films.

Grisly deaths in cartoons were common – shootings in Bambi, Peter Pan and Pocahontas; stabbings in Sleeping Beauty and The Little Mermaid; and animal attacks in A Bug’s Life, The Croods, How to Train Your Dragon, Finding Nemo and Tarzan.

Notable early screen deaths included when Nemo’s mother is eaten by a barracuda, just four minutes and three seconds into Finding Nemo; Tarzan’s parents being killed by a leopard four minutes and eight seconds into Tarzan; and Cecil Gaines’s father being shot in front of him six minutes into The Butler.

After taking account of total running time and years since release, 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.

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.

The study also suggested that parents, characters’ nemeses and children were more often the first casualties in cartoons, whereas the main protagonist was the most likely to be killed off in films for adults.

Only cartoons in which the main characters were either human or animal were included in the analysis, as it is not clear if the concept of death among ‘humanised’ objects, such as cars and toys, exists.

Violent content was also compared with that from the two top-grossing films for adults released in the same year as each of the cartoons, excluding those tagged as ‘action’ or ‘adventure’, because these are often marketed to children. Film genres included horror such as The Exorcism of Emily Rose and thrillers such as Pulp Fiction and Black Swan.

The genre and years since the film’s release were found to have no bearing on the results. And there was no evidence to suggest that the level of violence has changed in children’s films since Snow White and the Seven Dwarves, almost 80 years ago, when Snow White’s stepmother, the evil queen, was struck by lightning, forced off a cliff and crushed by a boulder while being chased by the dwarves.