Key Health Communication Theories

Why This Matters

Health communication theories aren't just abstract frameworks—they're the blueprints behind every successful public health campaign you've ever encountered. When you see an anti-smoking ad that makes you feel vulnerable, a fitness app that tracks your "stage" of change, or a viral health story that moves you to action, you're witnessing these theories in practice. Understanding why certain messages work helps you analyze campaigns critically and design interventions that actually change behavior.

On the exam, you're being tested on your ability to match theories to real-world applications, explain the mechanisms behind behavior change, and compare how different theories approach the same problem. Don't just memorize definitions—know what psychological lever each theory pulls and when a campaign designer would choose one approach over another. Master the underlying logic, and you'll be able to tackle any scenario the exam throws at you.

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Individual Belief and Perception Models

These theories focus on what's happening inside a person's head—their beliefs about risk, their confidence in taking action, and how they weigh costs against benefits. The core mechanism is cognitive appraisal: people evaluate threats and their own capacity to respond before deciding to act.

Health Belief Model (HBM)

• Perceived susceptibility and severity—individuals must believe they're personally at risk and that the health threat is serious enough to warrant action
• Perceived benefits vs. barriers—behavior change happens when the expected benefits outweigh the costs, obstacles, or inconveniences of taking action
• Cues to action—external triggers like symptoms, media messages, or doctor recommendations prompt people to move from awareness to behavior

Extended Parallel Process Model (EPPM)

• Fear appeals require balance—messages must create enough perceived threat (severity + susceptibility) to motivate action without overwhelming the audience
• Efficacy is the key variable—if people don't believe they can take effective action (self-efficacy) or that the action will work (response efficacy), fear triggers avoidance instead of change
• Danger control vs. fear control—high efficacy leads to adaptive responses; low efficacy leads to denial, defensiveness, or ignoring the message entirely

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Intention and Behavioral Control Models

These theories examine the gap between knowing something is good for you and actually doing it. The mechanism here is intentional processing: attitudes, social pressure, and confidence combine to form intentions, which then (sometimes) translate into action.

Theory of Planned Behavior (TPB)

• Intention as the proximal predictor—behavior is best predicted by how strongly someone intends to act, not just their knowledge or attitudes
• Three determinants of intention—attitudes toward the behavior, subjective norms (what important others think), and perceived behavioral control all shape whether someone forms an intention
• Perceived control affects both stages—feeling capable influences not just intention formation but also whether intentions convert to actual behavior

Transtheoretical Model (Stages of Change)

• Five distinct stages—precontemplation (not thinking about change), contemplation (considering it), preparation (getting ready), action (doing it), and maintenance (sustaining it)
• Non-linear progression—people cycle through stages, relapse, and re-enter; effective campaigns meet people where they are rather than assuming everyone starts at zero
• Stage-matched interventions—a person in precontemplation needs awareness-building, while someone in preparation needs concrete action plans and skill-building

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Social and Environmental Influence Models

These theories recognize that behavior doesn't happen in a vacuum—we learn from others, respond to social pressure, and exist within communities that shape our choices. The mechanism is social learning and normative influence: we model behavior we observe and conform to what we believe others expect.

Social Cognitive Theory (SCT)

• Reciprocal determinism—behavior, personal factors (like beliefs), and environment constantly influence each other in a dynamic feedback loop
• Observational learning and modeling—people acquire new behaviors by watching others, especially credible or relatable role models, succeed or fail
• Self-efficacy as the linchpin—belief in one's ability to perform a specific behavior is the strongest predictor of whether someone will attempt and persist at change

Social Norms Theory

• Actual vs. perceived norms—people often overestimate how much their peers engage in risky behaviors (like binge drinking) and underestimate healthy behaviors
• Misperception drives behavior—when people believe "everyone does it," they're more likely to conform to that imagined standard, even if it's inaccurate
• Correcting misperceptions—campaigns that reveal actual norms ("Most students drink 0-4 drinks when they party") can shift behavior by removing false social pressure

Diffusion of Innovations Theory

• Adoption spreads through social systems—new health behaviors move through communities via communication channels, opinion leaders, and social networks
• Five adopter categories—innovators (2.5%), early adopters (13.5%), early majority (34%), late majority (34%), and laggards (16%) adopt at different rates based on risk tolerance and social position
• Innovation attributes matter—relative advantage, compatibility, complexity, trialability, and observability determine how quickly a new practice spreads

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Message Processing and Persuasion Models

These theories focus on how messages work—what makes some arguments stick while others fade, and why storytelling can bypass resistance. The mechanism is cognitive and emotional processing: how deeply we engage with information determines its lasting impact.

Elaboration Likelihood Model (ELM)

• Two routes to persuasion—the central route involves careful evaluation of arguments (high elaboration), while the peripheral route relies on shortcuts like source attractiveness or message length
• Motivation and ability determine the route—audiences who care about the topic and can process complex information take the central route; others default to peripheral cues
• Central processing creates durable change—attitudes formed through deep thinking are more resistant to counter-persuasion and more predictive of behavior

Narrative Persuasion Theory

• Transportation is the mechanism—when audiences become absorbed in a story, they lower their defenses and are less likely to counter-argue against the message
• Identification with characters—viewers who see themselves in protagonists adopt their attitudes and intentions, making testimonials and case studies powerful tools
• Emotional engagement enhances recall—stories create emotional resonance that makes health information more memorable and personally relevant than statistics alone

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Media Influence Models

This theory examines how mass media shapes not just individual attitudes but collective priorities and public discourse. The mechanism is salience transfer: media attention signals importance to audiences.

Agenda-Setting Theory

• Media doesn't tell us what to think, but what to think about—the issues that receive prominent coverage become the issues the public perceives as most important
• First-level vs. second-level agenda-setting—first-level affects which issues matter; second-level (framing) affects how we interpret those issues
• Strategic implications for campaigns—health communicators must compete for media attention and frame issues in ways that resonate with journalists and audiences

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Quick Reference Table

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Self-Check Questions

1. A public health campaign shows statistics proving that most teens don't vape, despite what students believe. Which two theories best explain why this approach might work?

2. Compare and contrast how the Health Belief Model and EPPM approach fear-based messaging. When might a fear appeal backfire, and what variable determines the outcome?

3. A patient knows smoking is harmful and wants to quit but hasn't taken any steps yet. According to the Transtheoretical Model, what stage are they in, and what type of intervention would be most appropriate?

4. An FRQ asks you to design a campaign promoting HPV vaccination among college students. Which theory would you use if the target audience is highly motivated and analytical? Which would you use if they're resistant to traditional health messaging?

5. Explain how Social Cognitive Theory's concept of self-efficacy connects to the Theory of Planned Behavior's perceived behavioral control. How are these constructs similar, and how might they lead to different intervention strategies?