Candy tampering on Halloween is not widespread or cause for worry but is a myth fed by social tension, according to a sociology study.

Sociologists Joel Best and Gerald Horiuchi studied the phenomenon of Halloween sadists who hand out dangerous treats to children. They gathered newspaper accounts of incidents over a 27-year period, and discovered only 76 reports of tampering.

Injuries were involved in only 20 cases. Only two involved death, and these two deaths were later proven to be caused by family members of the children.

The authors also concluded that many of the reports were hoaxes. Follow-ups on the stories found that a majority of the 76 cases were made up. Some children tamper with treats themselves for the attention they receive upon ‘finding’ evidence of tampering.

Candy tampering is an “urban legend,” the authors said. An urban legend is a story spread by word of mouth that describes dangers in modern life. The tampering myth uses two elements of urban legends: poisoning food and threats to children.

Growth of an urban legend is mostly through word of mouth. Usually someone trustworthy tells a story of this type, and it gets passed on. Other examples of urban legends are children kidnapped from shopping malls or the mouse in a cola bottle story.

These stories originate in true but isolated incidents, and are fed by the media. Every year, along with the coverage of any tampering incidents from across the country, the media warns parents against the dangers of trick or treating, including checking the candy their children bring home.

Also, hospitals offer to X-ray treats, feeding the fear that tampering is a widespread problem, the authors said.

Urban legends are powerful enough to alter the way people do things, they said. The Halloween sadist has changed the way Halloween is celebrated. More children have parties instead of trick or treating, and treats that aren’t commercial products are thrown out.

The authors said this legend probably grew out of the 1970s, when the press gave extensive coverage to child abuse as a major problem in the U.S. Social tension grew from the idea that all children were vulnerable in all sectors of society.

This scared parents enough to evaluate their trust in society as a whole. Sending children out to go to strangers’ houses became a prospect full of danger, the authors said.

Worry grew and so did the stories of Halloween sadism, becoming larger than the truth of the incidents.