How Do You Change Behavior? “Grossing” People into Washing Hands
By Fiorenzo Conte
Many public health interventions aim to change people’s behavior. However, there is growing skepticism surrounding whether such behavior change interventions do actually change behavior. A post on the World Bank blog stresses that there is lack of evidence supporting the claim that behavior change programs convince people into changing behavior. In the case of HIV prevention programmes and changed sexual behaviors, what some thought to be the effect of such a program was, infact, the response of people to the observed increase in death rates. However, as the improvement of health is contingent upon getting people to acquire new habits, the question how do you change behavior remains pivotal. Some researchers are now convinced that a potent natural instinct can be harnessed for the survival of people: the ick factor or commonly known disgust.
Different researches (see here and here) have argued that the instinct of disgust has been developed over generations as part of an evolutionary process to protect the human body from external pathogens. Such thesis is supported by the fact that the cues or object which cause diseases are the same cues which elicit disgust. Feces, urine, vomit and spoiled food are in fact not only potent disgust elicitors but also the source of “over 20 known bacterial, viral and protozoan pathogens”. The most important of such diseases is diarrhea which is caused by a variety of bacterial, viral or parasitic organisms and is associated with unsafe hygiene practices such as washing hands without soap. This thesis of disgust as disease avoidance mechanism, developed in an evolutionary fashion, is further supported by the fact that cues which elicit disgust are consistent across cultures: most of the disgust elicitors are not in other words cultural specific.
What does this mean for public health? It means that public health campaign should aim to gross people out of their habits: by associating unsafe hygiene practices with a disgust elicitor, people can be convinced to drop that habit. Research conducted by Valerie Curtis from London School of Hygiene and Tropical Medicine in Ghana and India reveals that there is an instinctive search for hygiene by mothers to avoid object and smell which elicits disgust. The belief that some people do not value hygiene is disproven by the study which show that mother see being clean and neat as fundamental component to nurture their children and enhance their social status. By investigating hand-washing practices in Ghana it turned out that mothers often do not use soap after using toilet because their hands look clean. The campaign designed therefore revolved around the slogan “there is something on your hands, wash it off with soap”: to make visible something revolting about your habits can be instrumental in getting the person dismiss that habit.
Another thing which emerged from studies about disgust is the fact that to disgust people one needs to talk about the very object which causes disgust. A campaign designed following this insights was implemented in Bangalore where two role model characters were designed to improve villagers hygiene: one disgusting as she makes treats of mud and never washes her hands (see the picture) and one, Supermom, who follows the opposite, proper behavior. Such a campaign not only aims to disgust people but also, by building upon behavioral science insights, to show people not why but how they can change their behaviors.
Some evidence is emerging that disgust-based interventions are better at promoting hand hygiene compared to other interventions. As diarrhea remains the second leading cause of child death worldwide, we find out that nature has equipped us with a defense against this type of infectious disease: to leverage the power of the ewww factor in order to save lives.