What are you afraid of?  Probably a lot of things.  If there is something you are afraid of, you will avoid it.  That’s what fear appeals do, they make you fear something to avoid it.  Fear appeals can be used in good ways (think CDC’s anti-smoking campaign).  Some in not so good ways (think of Dr. Wakefield’s Lancet study forever incorrectly linking the MMR vaccine to autism).  The Protection Motivation Theory first developed in 1975 was designed to explain fear appeals.  Here is a look at the model:

Essentially this theory boils down to how severe the unhealthy behavior is versus how vulnerable you think you are to the behavior’s negative outcomes minus the rewards of continuing the behavior.  Then will the new behavior mitigate the negative effects and can you change the behavior minus the costs of performing the new behavior.  Take these together and you have the motivation to protect yourself.

Fear appeals play up the negatives only.   There is some question of whether or not fear appeals are effective in the long run.  Fear appeals only work if the person feels they can implement the new behavior (Kok, Bartholomew, Parcel, Gottlieb & Fernandez, 2013).  There is also the other side which is known as “Fear of Fear” which is when health officials are too afraid the raise the alarm over something dangerous because they incorrectly believe the public will run around like the panicked citizens of Tokyo in the movie Godzilla (Sandman & Lanard, 2003).

Fear is also different depending on culture.  For example, the US used creepy voices of dead ancestors to strike fear into the Vietnamese during the Vietnam War (link to YouTube video).  That would not work here in the US because there is a different belief system.  If a fear appeal is used on different cultural groups, there needs to be some thought into what causes fear over and over, versus something that only works once.  Think about a parent who threatens to kick their kids out of the house, but never follows through.

I think we need to be cautious in using fear appeals.  They should be used when the outcome is severe.  They don’t work in cases like high blood pressure and heart disease because we have medication to mitigate the threat.  However, it works great for things like smoking and Zika.  I don’t think anyone wants to live the rest of their lives in a horrible state or have a baby with unusually small skull.  Too many fear appeals and the public will stop listening to our messages.