'Sex and parents': Disturbing reason people turn into cannibals finally revealed

Naked and holding an axe, a German cannibal killer stands in his sandals and socks in the basement where he murdered and chopped up a willing victim he had met online.

New research has revealed why people turn into cannibals, and there are two types we should be wary of.

While evidence of cannibals can be found stretching back thousands of years, cannibals are rarely found in the modern age, except for in extreme circumstances.

Scientists are looking at the history of a group of five pathological cannibals kept in a psychiatric facility, and have uncovered there are two types of cannibals.

Cannibalism in humans could be down to a perverted interest in sex and your parents, new research has revealed.

Published in the Journal of Forensic Science, it was found those who experience forms of sexual desires which are gratified by dangerous activities, known as paraphilia, can turn to cannibalism.

The others are those who suffer from severe psychotic mental illness.

According to the American Psychiatric Association, paraphilia is a "sexual desire or behaviour that involves another person's psychological distress, injury or death, or a desire for sexual behaviours involving unwilling persons or persons unable to give legal consent".

The researchers said "ego and narcissism are the central issue, with a desire to overcome deep-rooted frustrations by means of an extraordinary act".

"Feelings of humiliation seem to be the trigger, and both patients assaulted their victims at a time when they suffered a loss of self-esteem."

The other group suffered severe schizophrenia, with cannibalism "a self-defence reaction to a perceived threat of destruction".

"Survival depends on the annihilation or assimilation of the other."

Over a 20-year period the researchers studied five medical cases of male patients aged between 18 and 36 who had practised cannibalism and were patients at a psychiatric hospital in Villejuif, France.

For the study the patients were split into two groups: those with severe schizophrenia and those suffering from mixed personality disorder "with sadistic and psychopathic features associated with paraphilia".

It was found all the patients were found to have dysfunctional childhoods that exposed them to sexual abuse, domestic violence or emotional neglect.

In May this year a 12-year-old schoolgirl claimed she had eaten human brains and flesh while on the run with paedophile Arkady Zverev.

Zverev died in custody before his trial for murder, cannibalism and raping a child.

Despite the girl confessing to eating a murder victim, she escaped prosecution because she was below the age of criminal responsibility and was not involved in the killing.