Roller coaster phobia combine substantial heights with seemingly insignificant support, as well as free-falls and the illusion of uncontrolled drops. Because acrophobia involves an extreme fear of heights and falling, these conditions could cause someone who is an acrophobic to have an extremely negative reaction to riding roller coasters. Claustrophobia involves two parts, fear of physical restraint and fear of suffocation. The safety harnesses and enclosures on some rollercoaster and other rides are very restrictive, in order to protect the riders from harm. In addition, the speed of these rides can cause air displacement that makes it difficult for riders to catch their
Appeal to fear are often used in marketing and social policy, as a method of persuasion. Fear is an effective tool to change attitudes, which are moderated by the motivation and ability to process the fear message. Examples of fear appeal include reference to social exclusion, and getting laid-off from one's job, getting cancer from smoking or involvement in car accidents and driving. Fear appeals are "nonmonotonic", meaning that the level of persuasion does not increase in proportion to the amount of fear that is used. A study of public service messages on AIDS found that if the messages were too aggressive or