The extended parallel process model (EPPM) is a fear appeal theory developed by communications scholar Kim Witte that illustrates how individuals react to fear-inducing messages.[1] Witte subsequently published an initial test of the model in Communication Monographs.[2]
The EPPM was developed by Witte as a response to the significant inconsistencies in fear appeal literature, serving as an extension of previous fear appeal models, hence the use of 'extended' in name 'EPPM'. The model is originally based on Leventhal's Parallel Process Model – a danger and fear control framework that studied how adaptive protective behaviour stemmed from attempts of danger control.[3] It also significantly draws from Roger's Protection motivation theory, which proposes two responses to fear-inducing stimuli: threat appraisal and coping appraisal.
The model's main theory is that when confronted with a fear-inducing stimulus, humans tend to engage in two simultaneous ways of message processing: a perceived efficacy appraisal (cognitive processing) and a perceived threat appraisal (emotional processing). Differences in message appraisal then lead to two behavioural outcomes, with individuals engaging in either a danger control process or a fear control process. In the case of the message being perceived as having no element of threat, individuals do not exhibit a response, and the message is ignored. The EPPM states that the danger control process leads to behavioural change, while the fear control process does not.
Witte's EPPM expands on previous fear appeal studies by explaining the reasons for failure in fear appeals and reincorporating fear as a central variable in the model. This is also the first fear appeal model that outlines the relationship between threat and efficacy in propositional forms.
The EPPM concludes that a fear control process leads to message rejection, while a danger control process leads to message acceptance, leading to adaptive behavioural changes.
Witte's motivations for designing an updated fear appeal model was due to the declining role of fear in fear appeals. While initially, fear was the pinnacle of theoretical fear appeal literature, it was starting to be considered as a control variable in subsequent models. A lack of precision in the Parallel Process Model and empirical inconsistencies in the Protection Motivation Theory were also noted by Witte as reasons for formulating an extended parallel process model.
Two main components of large-scale public messaging that induce behavioural change are fear appeals and fear appraisals. Fear appeals are specifically designed to elicit fear and nudge individuals to adapt to the recommendations in the message. They find their use in public health campaigns and political adverts, and are designed to fit three main categories: message, behaviour, and the audience.[4]
Fear appraisals are the mental evaluations made in response to experiencing fear-inducing stimuli and are also known as threat appraisals. Fear appeal literature is primarily focused on understanding key fear appraisal processes in humans, with the intention of using it to drive social campaigns and behavioural interventions.
The EPPM uses persuasive fear-inducing messages to induce intended behavioural responses. Wittle details three main processes involved in fear appraisal: the fear appeal inputs, the message processing of the inputs, and the outputs, or action taken after evaluating the perceived threat.
According to fear appeal studies, a fear appeal has two components: a component of threat and a component of efficacy. These two components are further divided into two categories each. The threat component is composed of severity and susceptibility, while the efficacy component is composed of response efficacy and self-efficacy.
These four key factors, as defined by the EPPM, predict the likely outcome of communications that involve a fear appeal.
Threat variables
Efficacy variables
The outcome of fear appeals is determined by an appraisal, that is, the evaluation of the message as either dangerous or indifferent.
Appraisal Theory states that an individual makes either an emotional or affective response to external stimuli. The EPPM outlines two primary appraisals an individual makes in response to a fear appeal: a threat appraisal, followed by an efficacy appraisal.
After appraisals of the fear appeal, individuals then take action based on whether the threat is imminent or trivial.
The EPPM predicts three possible outputs after the fear appraisal is carried out:
The EPPM model is mainly used in social and behaviour change communication (SBCC). Practitioners design a general communications program, such as a campaign or an advert, and then test the effectiveness of the program through implementation. SBCC methods in healthcare, education, and marketing have employed the EPPM to induce behavioural change in patients and customers.
Multiple versions of the EPPM are employed in health campaigns. For example, EPPM-based campaigns have helped increase colorectal cancer screening participation among young adults[5] [6] and increased HPV vaccination interest among LatinX.[7]
Other usages of EPPM lie in shaping public perceptions, such as in political adverts, climate change messages, and pandemic responses. [8] [9]
While the EPPM has been effective in health campaigns and behavioural change interventions, there are limitations that have been pointed out through rigorous meta-analytical studies.
Reviews have highlighted the many applications of the EPPM model in its 20 years since initial publication [10] but significant theoretical questions on the operationalization of key constructs remain and not all of its hypotheses have received empirical support.[11]
Lucy Popova's The Extended Parallel Process Model: Illuminating the Gaps in Research