The body which decides movie ratings is to put a new emphasis on the effects of horror films under new guidelines published today.
The British Board of Film Classification said in future it will further scrutinise the " psychological impact of horror" examining "gore" among the strong visual detail which may be featured in films.
It will also be tougher on strong language in films aimed at family audiences but will be more "flexible" for films at the 15 classification after public research showed that context rather then frequency was the key factor for viewers.
The BBFC said today - as it published new guidelines on its ratings policy - there will greater weight given to the "theme and tone" rather than simply specific scenes and details on screen, particularly at the 12A/12 and 15 levels.
It will also pay further attention to sexual content after an extensive public consultation - involving around 10,000 people - showed there was concern about "the sexualisation of girls and pornography", with the content of music videos and access to online porn said to be "special worries".
During the research people were asked how issues such as sex, violence and bad language should be handled, looking at 60 films and videos. The vast majority backed the classification levels of films they had seen recently, with nine out of 10 believing that The Woman In Black - which has brought the most complaints of the past four years - had been correctly issued with a 12A certificate.
The BBFC's director David Cooke said: "Our new classification guidelines reflect explicitly concerns raised by the public during the 2013 consultation and will, I believe, ensure that we continue to be in step with what the public wants and expects in order to make sensible and informed viewing decisions."
He admitted that even after 12 years of use, some viewers were still confused by the 12A rating.
"We and the film industry will work during 2014 to improve understanding of this very important rating," he said.